Jet is one of the Rocket Brothers, lead by his big brother Rocket.
Jet is darker in color than Rocket but paler than Missile.
Jet is less rightful and hopeful than his big brother, strongly believing that the strongest will always rule.
He wishes to gain more territory and doesn't care if someone gets killed because of it.
When Jerome says that he is ready to sacrifice himself for Weed, Jet mentions that such fools don't exist anymore. While Jerome proves his attitude right, Jet gets wounded and angered, wishing to kill Jerome next time they meet - unlike Rocket who was impressed by Jerome's attitude.
He is shocked when Rocket leaves him and Missile, not wanting to be on the side of the "loser" even if it meant killing his own brother.
Ginga Densetsu Weed
Jet is the brother of Missile and Rocket, and a runner for Hōgen and gets the task to find Gin, Akame and John. Jet takes Reika as hostage to make Gin surrender. The brothers get a new task - to capture Weed. Rocket joins the pack as a spy, and when he sees the chance, he kidnaps Weed.
As the brothers are about to kill Weed, Jerome shows up and fights the brothers. The pack interrupts the fight, but Weed spares them, and Rocket joins Weed, moved by his kindness. Jet and Missile go back to Hōgen, where they're killed because Rocket joined Weed.
Jet, Missile and Rocket were not Hōgen's minions but as guests. After having a feast of deer meat as presented by Hōgen, he and his brothers were given a task - to capture Weed. On their way, they bumped onto the blind Great Dane, Ben and the old Saluki, Cross.
Fortunately, the Borzoi Brothers did not harm them and went on with their duty. After Missile succeeded in snatching Weed off from his pack, the brothers were deciding what to do with the puppy when Jet tried to attack Weed but was stopped by Jerome who showed up just in time. The Borzoi Brothers fought Jerome until Weed's pack interrupted it that they ran away empty-handed. However, Rocket decided to join the Ōu Soldiers from realizing his true purpose from Saburō's words and left his brothers behind.
Shortly after that, Jet and Missile returned to Hōgen only to be killed by him and his minions (Jet was killed by Hōgen's minion, then Missile was killed by Hōgen himself). In the final battle against Hōgen, Jet and Missile appear as ghosts along with the other soldiers who died in battle. They both speak to Hōgen after Smith.
See more pictures in Jet/Gallery.