Jasper had tangerine skin with reddish-orange markings on her face and arms. She had amber eyes and plump lips. Her gemstone was located where a normal nose would be. She had thick, beige-white-colored flowing hair. Physique-wise, she was the archetype Quartz Gem soldier; she had a muscular body and stood both taller and wider than Garnet, an indication of her immense strength and durability.
She wore a sleeveless bodysuit, similar to Peridot's, with a dark mahogany V-neck collar and a yellow diamond in the center. The torso of the bodysuit is maroon, and the legs are dark mahogany. She wore red boots with dark red toe caps.
After her Corruption, she became similar in body type to the wolf-like Snow Monster she fused with, gaining teal spikes across her body, losing her eyes, and gaining two ram-like horns on the side of her head. Spikes protrude from multiple areas of her body, and she appears to have beige-colored mane/tuft of hair growing around her neck. Blotches of green and orange make up her skin, and her teeth became sharp and orange.
After getting healed from her corruption by Steven and the Diamonds in "Change Your Mind", she still wears a sleeveless bodysuit, however the torso now has a different design. She now wears a brown-orange square neck tank top and between is a pale orange triangle with a brown-orange keyhole shape, which contains a small pale orange triangle through it. She also keeps the teal-colored markings and horns from her corruption.
Jasper is a bully in the truest sense. Deep down, she's afraid there's something wrong with her, so she has to feed her ego. She has to put other Gems down to stay on top. Who she is and where she's from gnaws at her all the time. She has a fantastic reputation, she's considered the greatest Quartz soldier produced on Earth, and that might impress other Gems, but it will never be good enough for her. She will always feel held back, and she'll always feel the need to go further to get ahead.
The Gems live in a society with a very rigid social order and caste system, and Jasper has completely bought into that, and her self-worth is attached to it. Because she loves honor, fighting, making her mark, and winning the battle, she'll actually go against her programming a little bit just to be the winner. So she can be self-destructive at times. She is tragically obsessed with proving her superiority.
Jasper is very ruthless and headstrong, as well as an aggressive combatant. Assumed to be a high-ranking Gem warrior and veteran of The Rebellion, Jasper is very authoritative and militaristic; something that directly affects her subordinates, Peridot and Lapis Lazuli. She doesn't care about them, doesn't bother to heed their warnings or concerns, and will not hesitate to browbeat them into submission if they complain or disagree with her. The importance she puts on one's own battle prowess also leads her to look down upon any of whom she considers to be a weakling. She despises the act of fusion specifically, as seen when she announced, "Fusion is just a cheap tactic to make weak Gems stronger!". Even after Garnet defeated her and crashed the Gem Warship, she didn't consider it a loss, because she believed Garnet only beat her because she was a fusion.
Her attitude towards those whom she considers to have proven themselves in battle, however, is a much more positive and respectful one. When she first arrived on Earth, she quickly dismissed Garnet, Amethyst, and Pearl as weaklings not worth her time. She did, however, express disappointment when she found out that Rose Quartz wasn't present because she wanted to face her in battle, as she respected her as the military commander of the war. Likewise, this caused her to be confused and frustrated as to why Rose had apparently shape-shifted into a "weak human boy" to fight her.
Jasper can be hypocritical; the prospect of a humiliating defeat at the hands of the Crystal Gems repulsed her so much that in a last desperate attempt to seize victory, she coerced Lapis Lazuli to fuse with her to form Malachite, apparently disregarding her previous opinion on fusion.
The reasoning for Jasper's aggressive personality and hypocritical actions is because of her origins on Earth - the failed Gem colony planet. Because Earth is regarded as a failure on Homeworld, Jasper has developed self image issues, believing that she might be a failure herself due to being made on Earth. In order to prove to herself that she isn't a failure, Jasper will insult others and constantly have the desire to prove her superiority to others in order to keep her ego intact. Jasper has to make sure that she always comes out on top so her thoughts of being a failure don't eat her up, and if she has to break rules to win, she will. As shown in "Crack the Whip", Jasper talks down to Amethyst while brutally beating her up to show herself how powerful she is. After facing constant defeat at the hands of the Crystal Gems, Jasper becomes desperate and even captures Corrupted Gems in order to ensure her victory. Jasper even fuses with one, and becomes corrupted herself. Once Jasper is semi-corrupted, the thoughts of being a failure and the rage she feels for Rose Quartz causes her to ultimately take on a monstrous form. As seen in "Chille Tid", if Jasper can't come out on top, she becomes enraged and driven to an almost insane state. Rebecca Sugar explains in the podcast, that it comes from her origins by being made in the Beta Kindergarten who is considered a failure on the Earth colony, making Jasper wanting to prove her worth because everyone around her knows she’s from Earth’s Beta Kindergarten and therefore must be flawed on some level, she feels she can never escape being associated with Rose Quartz even though they were both from different sides, Ian Jones state that she feels she’s fundamentally wrong and that she doesn’t deserve the reputation she has as an example of how the system on Homeworld can fail Gems who don’t quite fit the mold; she is a model Gem, but she never internally feels she deserves her reputation.
Jasper also holds a vendetta against Rose Quartz for being the one to shatter Pink Diamond, and holds absolutely no respect for the Crystal Gems. The only reason Jasper returned to Earth wasn't to escort Peridot like she was supposed to but to destroy Rose and the remnants of her army.
I see how you do it now, Rose. You want Gems after they're worthless, you wait until after they've lost. Because when you're at the bottom... you'll follow anyone who makes you feel like... less of a failure...
When asked why Jasper, unlike Peridot and Lapis, refused help from Steven, Rebecca Sugar says:
Jasper is very different than Peridot and Lapis. Unlike them, she has a deep hate for herself because of her origins on Earth. She is determined to never be weak or vulnerable. So at the point when she's the lowest, there's no way she'd ever accept help, because she believes she doesn't deserve it.
Peridot and Lapis both believed they deserved better than what happened to them, but not Jasper. She went back to Earth to face her demons, and she lost. She's consumed by her own self-pity.
She's even got frictional rock melt. It's glass all the way to the back. Actually, I uh, I've never seen an exit hole this perfect... Wait, no! Don't fight her! Are you not seeing this? She's the ultimate Quartz!
All Era-1 Gems have various powers, including the ability to invoke a weapon, change shape, and strength, agility, speed, and skill beyond human capabilities. Jasper can also take refuge in her gemstone after being wounded to heal. She is also capable of fusion, as shown when she fuses with Lapis Lazuli to form Malachite and later a Corrupted Gem to form a centaur-like monstrosity.
Being a Quartz Gem, her creation was to fit the role of a soldier within Gem culture. According to Peridot (a certified Kindergartener skilled enough to identify the type of Gem that emerged from a particular exit hole with a glance), Jasper is the 'ultimate' Quartz, made completely perfect, implying she is a superior specimen even among her own kind. She is considered the greatest Quartz produced on Earth. As such, she has incredible amounts of physical strength and stamina, making her one of the most physically imposing Gems seen thus far. She is also strong of will, as it takes all of Lapis' concentration to subdue Jasper. Jasper's strength is further emphasized in "Alone at Sea" when she climbs up the anchor chain on the side of the ship, making the entire ship shake and creating a loud thumping sound. This happens once more when Jasper steps onto the ship.
Jasper is also one of the most durable Gems ever shown in the series, being capable of withstanding the point blank explosion of a Gem Warship's reactor, the following crash and explosion of the entire ship unprotected, being hit with enough force to send her flying over the horizon, and being struck with enough force by Rose Quartz's Sword (which has the power to easily destroy a Gems' physical body) to be driven through a Corrupted Gem (poofing it in the process), all without poofing once. It takes Peridot driving a piece of scrap metal clear through her chest and out her back to finally poof her, and even then that was only after she had been corrupted.
When fused with Lapis Lazuli, Ruby, Sapphire, Amethyst, Pearl, Ice, Peridot, Rose Quartz, Marshallsussmanite, and Emerald, they form Cadmoindite.
Crash Helmet Proficiency: By gathering her resolve and thirst for battle, Jasper is able to summon her weapon; a tangerine, crystalline helmet. The helmet acts both as a weapon and armor; a hammer-like protrusion in the front of the helmet allows her to use it to charge, slam, and head-butt her opponent, while a clear orange tinted visor extends down, covering the upper part of her face. The sturdiness of the helmet rivals that of Garnet's gauntlets, as Jasper was shown continuously countering her attacks.
Martial Arts: Further reflecting the similarities between herself and Amethyst, Jasper is likewise prone to mixing up her weapon-based attacks with martial arts moves, such as grappling, throwing, or simply punching her opponent. Due to the nature of her weapon, the two styles mix seamlessly and combine into a powerful, but ultimately reckless fighting style with immense collateral damage.
Headbutting: Jasper is shown to be able to head-butt without her weapon. This version, although weaker without her crash-helmet, still has the potential to knock out a human being.
Piloting: Whilst Jasper herself has never demonstrated this ability, it is implied by Doc in "Back to the Moon" that Jasper can pilot Gem ships, such as a Roaming Eye.
Comet Charge: Jasper can lunge at her foes with alarming speed and power, as evidenced by the attack breaking through layers of hard gemstone. While she performs this attack, a fiery aura is formed around her.
Spin Dash: Jasper can rapidly roll in a ball-like shape to attack enemies. While Amethyst was shown to have this ability as well, it seems that Jasper's version is more powerful. As shown in "Jailbreak", Jasper can use the technique to dash across a spacious room and plunge into the air.
Gem Destabilizer: Homeworld Gems, in addition to their summonable weapon, seem to carry a personal defense weapon known as Gem Destabilizers — extremely potent, non-lethal tools used to subdue enemy Gems. Jasper is seen using this weapon on Garnet in "The Return". She attempts to use it again in "Jail Break", but Garnet pried it from her hand and broke it immediately afterward.
Jasper holds a strong animosity towards Rose, due to her being the one who shattered Pink Diamond. She accepted the mission to escort Peridot on Earth because she was looking forward to beating Rose "into the ground" in order to avenge her Diamond. Despite this, Jasper expresses a great deal of respect towards Rose for her role as the military commander of the war, although she does harbor disgust towards Rose's love for the Earth and will to fight for the planet. Jasper believes that Steven is Rose, and treats him as such.
In "Chille Tid", Jasper is shown to harbor a vendetta against Steven and tries to attack him upon seeing him. However, Lapis manages to restrain and suppress Jasper.
In "Super Watermelon Island", Jasper's personality through Malachite shows that she bears an animosity towards Steven, even referring to him by name instead of Rose (though it is likely Lapis' connection within before Jasper steals back control), to the point where the Watermelon Steven's resemblance of him angers her. However, while Steven and Jasper have by no means a friendly relationship, he did call out to her when she fell into a crack in the earth, apparently valuing her life nonetheless.
In "Alone at Sea", Jasper is still unaware that Steven and Rose are not the same, referring to him as "a dulled down version of Rose Quartz". Despite her dislike for him, she does not attempt to harm him until Lapis rejects her pleas to reform Malachite. When Steven continues to defend Lapis, Jasper blames Steven, charging at him in an attempt to shatter him before Lapis intervenes.
In "Crack the Whip", Jasper insulted Rose for having a defective Quartz like Amethyst and stated she must have low standards when Amethyst counters by saying that Rose thought that Amethyst was perfect the way she is.
In "Earthlings", Steven finally tells Jasper that he is not Rose and tells her his name, though she continues to refer to him as Rose. Jasper refuses Steven's help when he tries to heal her corruption because she comes to her own conclusion that Rose takes advantage of weakened or defective Gems like Amethyst. Feeling that by feigning concern for Gems will convince them to follow her, Jasper believes that Rose's compassionate nature (and Steven's by extension) is a facade. Enraged, Jasper screams at Steven that she's been fighting her entire life because of what Rose did to her colony, her planet, and Pink Diamond. Jasper's last words before becoming corrupted also reveal that she came back to Earth to defeat Rose because of what she did to Pink Diamond.
When she was healed in "Change Your Mind", Jasper once again tried to attack Steven, only to see him surrounded by several other Jaspers. Amethyst then proceeds to inform her about the truth, and Jasper meekly sinks into the pool.
Due to the Crystal Gems being traitors who staged a rebellion against their Homeworld, and the fact that Jasper fought on the side of the loyalist Gems in the conflict, her view on the Crystal Gems is naturally a negative one. She is eager to settle the score with them; so much so that she expresses disappointment in the fact that the only ones left from Rose's army are the Crystal Gems. She initially considers them unworthy for her to fight personally and simply orders Peridot to blast them with the Gem Warship.
Jasper appears to do whatever she can to get even with the Crystal Gems for everything they have done, such as stopping the Earth's colonization. Some of Jasper's actions to end the Crystal Gems' existence involved imprisoning them in order to take them to Yellow Diamond, forming Malachite to shatter them, and creating her own army of Corrupted Gems to compete with the Gems.
In "Super Watermelon Island", she takes control of Malachite to 'have some fun' and destroy the Crystal Gems, who have fused as Alexandrite. During the fight, she uncharacteristically thanks the Crystal Gems for proving her previous opinion wrong – that fusion is not just some cheap trick. To 'thank' them, she attempts to unfuse Alexandrite by squeezing her with hands created by water and freezing them, as she sees there is room for only 'one abomination'.
In the podcast, it stated that Jasper has been told since she emerged that she was perfect, and that’s what she wants to be and considers the Crystal Gems a band of uplifted flawed Gems, this is why Steven wasn’t able to recruit in his traditional way, as Jasper didn’t want to change sides.
Jasper was put in charge of overseeing Lapis, following her return to Homeworld. After imprisoning her, she forces Lapis into being hers and Peridot's informant as a way to help them find and capture the Crystal Gems. Jasper treats Lapis very roughly and sends her back to her cell after finding out she withheld information from her, despite Lapis saying it is not relevant to the mission. When Jasper attempts to coerce Lapis into fusing with her to defeat the Crystal Gems, Lapis eventually agrees. The two fuse together to form Malachite, with Jasper initially appearing to be the dominant personality. Before Jasper can make use of her new form, Lapis regains control of her hydrokinetic ability to bind and imprison their fusion beneath the ocean. While trapped beneath the ocean, Jasper is tenacious in her efforts to either regain control of Malachite or escape the fusion. They are later unfused in "Super Watermelon Island" after being defeated by Alexandrite.
In "Alone at Sea", Jasper begs Lapis to re-fuse with her, claiming they were better together than apart. She claims that Lapis is a monster, and only she could handle that power. After being rejected, she becomes enraged and attempts to shatter Steven only to be thrown into the ocean by a water hand invoked by Lapis.
Jasper quickly recognized that Amethyst is a Quartz Gem soldier much like herself, only an "overcooked runt", indicating that despite their shared heritage, she sees Amethyst as just another Crystal Gem rebel, and perhaps an inferior version of herself. In "Crack the Whip", she belittles and insults Amethyst over her inferiority, claiming that Rose must have low standards when Amethyst argued that Rose said she was perfect the way she is, which caused Amethyst to attack her in anger only to be defeated and poofed. Jasper then attempts to kill Amethyst by crushing her gemstone, forcing Steven and Connie to fuse into Stevonnie to rescue her, which shows that Jasper is willing to kill Amethyst. She also commented that if Amethyst was not defective, she could have been like Jasper herself. Despite being saved and regenerated, Amethyst is affected negatively by her defeat and the fact that Steven and Connie managed to ward off Jasper without her help, causing her to question her usefulness, having apparently taken Jasper's comments about her to heart. As of "Beta", Amethyst still holds a grudge against Jasper and trains extensively for a rematch against her, much to Steven's concern. In "Earthlings", with some encouragement from Steven, Amethyst finally overcomes her feelings of worthlessness and forms Smoky Quartz with him in an attempt to defeat Jasper once and for all. After Jasper was corrupted following her fusion with the Snow Monster and poofed by Peridot, Amethyst seems to take pity on Jasper and even refers to her as "Sis" (as they are both Quartz gems that were made on Earth) as she bubbled her gem.
When Jasper is healed in "Change Your Mind", Amethyst is the first to greet her as she surfaces from Rose's fountain, mouthing "Hey, sis".
"How can you side with Rose Quartz?! Why? Why protect this useless shell of a planet?"
"It's not a shell. There's so much life, living here. That's what I'm doing! I'm living here! I've been learning new things about myself all the time! Like how I can make metal do my bidding! The point being: Earth can set you free."
Jasper and Peridot seem to hold some tension between each other. Most of this seems to stem from the fact that Jasper is put in charge of escorting Peridot, as the Crystal Gems repeatedly hinder Peridot's efforts, forcing Peridot to report to her superior(s) and ask for additional help in the matter. Jasper pays little attention to Peridot's grievances and complaints, possibly as a result of Jasper looking down on Peridot, who is more of an intellectual/technician than a soldier. Peridot states in a message intended for Yellow Diamond that Jasper was her escort, though the Rubies sent by Yellow Diamond later clarified that Jasper was acting leader of the mission to Earth. In "Earthlings", Jasper seemed surprised to find that Peridot has joined the Crystal Gems, and no longer serves Homeworld.
Upon first seeing Smoky Quartz, Jasper commented that fusion was the only tactic the Crystal Gems had. After realizing she could not win against them, she exclaimed that she would not lose against yet another fusion. Ironically, this incited her to fuse with a Corrupted Gem, which ultimately lead to her own corruption.
Jasper and Garnet's relationship is very antagonistic, as Jasper's self-reliant outlook on life means that she looks down on Garnet for being a fusion. When she first meets Garnet, she refers to her as a "shameless display", implying she already knew that Garnet was a fusion. Her defeat at the hands of Garnet in a rematch pushes her to make the hypocritical decision to fuse with Lapis in an attempt to become stronger. This rash decision led to her confinement at the bottom of the ocean until "Super Watermelon Island".
As a Homeworld soldier, Jasper answers to Yellow Diamond but is not too loyal to her. While she strongly values and believes in the Diamond Authority, she is not as loyal as she could be. She easily disregards her primary mission of checking on the cluster and goes off doing her own thing, implying that while she answers to Yellow Diamond, she does not consider her as her true leader, which could be a reason as to why she still refers to Pink Diamond as her Diamond. Upon mistaking Steven for Rose Quartz, Jasper immediately ordered Steven to be captured and brought before Yellow Diamond. Their personal relationship is unknown, although in "Message Received" Yellow Diamond seemed less concerned about her than the ship she was on and in "Hit the Diamond", Yellow Diamond sent a team of Rubies to find and retrieve Jasper.
Not much is known about the relationship between Jasper and Pink Diamond, though from Jasper's ideology shows that she had a great deal of respect for her as she served under her. This respect continued as Jasper is still angered toward Rose Quartz for what she did to her former leader, never realizing the two were one in the same. Jasper continues to refer to Pink Diamond as her Diamond even after she was shattered, showing how much adoration she had for her. In the podcast, the reason Jasper bullies others is because of her pent-up feelings, and she expresses her heartbreak over Pink Diamond’s shattering through acting aggressively toward others.
In "Crack the Whip", Jasper is shown to be visibly disgusted when Steven fuses with the human Connie to rescue Amethyst, who Jasper had just defeated. As with Steven, Jasper refers to Stevonnie as Rose (likely due to the fact that they use Rose's weapons and possess her gemstone). When Stevonnie manages to put up a decent fight, Jasper expresses frustration at once again having difficulty fighting a fusion and retreats back into the ocean, swearing revenge.
It is not known if Jasper has met Eyeball, but it is shown in "Back to the Moon" that Eyeball looks up to Jasper as she is flattered when Amethyst (disguised as Jasper) tells her to write her report for her on Homeworld.
According to the Rubies in "Hit the Diamond", Jasper was the leader of Peridot's mission to Earth.
As of "Crack the Whip", Jasper appears to have taken residence in the ocean outside of Beach City, probably due to having been imprisoned there in months while fused as Malachite.
As of "Beta", Jasper has been shown to have been living in the Beta Kindergarten with her army of corrupted gems.
Jasper has been involved in the poofing of three Crystal Gems, more than any other Gem.
Ruby and Sapphire in "The Return" and Amethyst in "Crack the Whip".
In "Beta", Peridot describes Jasper as the perfect/ultimate Quartz, stating that she's "never seen an exit hole this perfect."
As of "Earthlings", she has become corrupted and bubbled.
She is the first gem to be seen corrupted on-screen, as well as the first gem to fuse with a Corrupted gem.
She is the Gem that confirms that Pink Diamond existed at some point, that both she and Rose served under her, and claims that Rose is responsible for whatever happened to her.
A detail confirmed that she wasn't 100% made for Yellow Diamond, because she refers to Yellow Diamond by her normal name, instead of "My Diamond" like other followers.
It is implied that Jasper knows how to pilot a Roaming Eye.
Prior to "Earthlings", Jasper was the longest recurring Gem antagonist who had not been caught and poofed by the Crystal Gems, the second being Peridot, though the latter reformed.
Ironically, Peridot was the one who poofed her in the end.
After being asked by a fan, Kimberly Brooks had stated that Jasper's voice was inspired by a Sears employee she had spoken to while looking for an appliance they no longer sold.
For a currently unknown reason, compared to the other corrupted Jaspers seen in "Gem Hunt" and "Earthlings", Jasper is the only Jasper-type Gem whose gemstone is not circular cabochons, but rather a three-faceted diamond-esque shape.
Rebecca Sugar confirmed in an interview that she will appear again.
Rebecca Sugar has also previously admitted that she would like to bring Jasper back by giving her a "redemption arc" in the series.
Kimberly Brooks mentioned at the 2018 L.A. Comic Con that she is waiting for the moment when Jasper will have a redemption arc/episode, and she hopes that Jasper will sing a song in it.