Jasper/History

Not much is known about the early history of Jasper, except that she fought in the first war 5,750 years ago against the Crystal Gems and respected Rose Quartz's leadership and tactics.

Season 1
In "The Return", Jasper arrived on Earth with the mission of being Peridot's escort, assigned by Yellow Diamond, while she checks progress on the Cluster. Upon observing the Crystal Gems, Jasper believes that they are a waste of her time. Jasper then ponders where Rose Quartz is because she was looking forward to fighting her. Jasper proceeds to insult each of the Crystal Gems and tells Peridot to blast them with the ship because she believes that she can easily take them all on by herself. To Jasper's surprise, the Crystal Gems survive the explosion thanks to Steven's shield. Jasper immediately recognizes the symbol being Rose Quartz's. She asks Steven, thinking he is Rose, why he took the form of a human boy. In response, Lapis Lazuli begs Jasper not to hurt him, which prompts Jasper to become enraged at Lapis for withholding information from her. Jasper then disregards the mission and wants to show Yellow Diamond what has become of "Rose". Garnet attacks Jasper but Jasper summons her Crash Helmet and causes Garnet to unfuse using her Gem Destabilizer. She lifts up Steven by his shirt, still thinking that he's Rose, and mocks him, explaining how the Crystal Gems are weak, and that Rose has failed. She headbutts Steven and places him, the other Crystal Gems, and Lapis, in jail cells on the Gem Warship.

In "Jail Break", while on the Gem Warship, Jasper tells Peridot that they are going back to Homeworld with the captured Crystal Gems and Lapis. Peridot disagrees, explaining to Jasper that the whole point of coming to Earth was to check progress on the Cluster. Jasper, once again, disregards the mission and tells Peridot that delivering Rose Quartz (Steven) to Yellow Diamond takes priority. Later, Jasper discovers that one of the imprisoned Gems is missing from her cell and finds Garnet in the center of the ship. Jasper is annoyed that Ruby and Sapphire are fused again and she explains to Garnet that "fusion is just a cheap tactic to make weak Gems stronger".

Garnet and Jasper then begin fighting; Garnet dodges Jasper's attacks and breaks her destabilizer. Jasper then spin dives at Garnet and causes both of them to fall through the deck and into the ship's engine room. While Garnet sings, she continues to fight with Jasper, once again dodging many of Jasper's attacks. Finally, Garnet catches Jasper and throws her into the ship's main power source, causing it to explode. Jasper crawls out of the ship debris, obviously injured, and explains to Garnet that she won only because she is a fusion. Jasper catches Lapis when she tries to fly away and seemingly persuades her to fuse with her. Lapis agrees and the two proceed to fuse into Malachite. However, Lapis chains up their fusion. Jasper struggles to escape and Lapis drags them both to the bottom of the ocean.

Season 2
In "Chille Tid", when Steven enters Malachite's Realm, it is revealed that Lapis has control of the fusion. Steven being there, however, distracts Lapis and Jasper momentarily takes control. Jasper appears tired and when she notices Steven, she becomes enraged. She crawls to Steven repeating the word "you" and when she becomes close, she tries to grab Steven but is stopped by Lapis who once again regains control.

In "Super Watermelon Island", the civilization of Watermelon Stevens on Mask Island attempt to sacrifice one of their number to Malachite in an effort to stop the earthquakes that troubled the island. Thanks to Steven's vision of the event, the Crystal Gems track her down, and fuse into Alexandrite to fight her. Lapis finally loses of their fusion and Jasper takes control. She releases the chains that kept Malachite back and is pumped to fight Alexandrite. As Malachite, Jasper states, "You know you're right, there really is something more to this fusion thing! It's not just a cheap trick, you've really shown me a whole new world of possibilities!" Malachite is defeated and forcibly defused by the Gems, with aid of the Watermelon Stevens. During the final moments of the fight, a Cluster-related earthquake took place, creating deep fissures in the ground. Jasper's unconscious body rolls down and falls into one of the cracks. What has become of her is unknown.