Jak has Blue and red quills with red hair and white furry chest, wears a sleveless light grey shirt with a brown jacket on top, Grey shorts, and are rolled up a little to his knees, white and orange shoes with straps on them and are ankle high, and a blue fox tail with red fur at the end.
Jak is a goofball who loves puns and pranks, he usually is happy and cheery unless in a fight, when he becomes a fighting machine that none of Eggmans robots could easily defeat.
Jak was born as a clone of Sonic, Shadow, and Tails DNA. He had been imprisoned along with his beloved sister Jewel. They were tortured and experimented on for years, seeing what would happen if they were separated for long amounts of time, or what would they do if they saw and interacted with Chaos Emeralds, until they were seven years old. During that time, Jak had been giving information to Sally Acorn and the Freedom Fighters of how to get in, infiltrate his base, and defeat him and get them out. that day Eggman planned on robotizing the two of them and make them eternal slaves to see if Robotized Mobians could interact with Chaos Emeralds. That was interrupted when Sonic, who was his idol and hero, came and destroyed the lab, and freed Jak and Jewel, and joined with Sonic as Freedom Fighters. They lived happily and having fun, fighting and defeating Eggman again and again. but one day,everything changed, when Dax attacked and severely injured Jewel. Jak only could hold her in his arms as she died. Jak was never fully the same again. He became more distant, more depressed, but with help, he came mostly back to normal, but had a habit of visiting Jewels grave every day, and mourning the day she died every year.
he eventually fully recovered after finding out Jewel was now a Neo Walker and could talk to him once in a while, and stopped mourning but vowed to defeat Dax once and for all. a few months later, he met Blaze for the first timeafter falling through a warp ring by accident. He liked her, because she was kinda like him. she knew what it was like to be alone, but he got along well with her and Marine. He then experianced a rift between blaze and sonic';s world and after it was fixed, Jak and blaze said their goodbyes, and promised to meet again.
Jak has the power to use chaos energy almost like Shadow the Hedgehog, but to a further extent, where he can not only use many chaos abilities, but also make constructs to use in battle or to train with, or use as a shield. Jak also has super strength, enough to rival Knuckles in strength. he has an ability called Chaos Sense, which allows him to sense Chaos Energy like Knuckles
Jak's abilities are to use chaos energy whenever he wants,he can make constructs with Chaos Energy, he can summon a sword that looks like a power ring with a hilt in the middle, with a blade made of a Green Chaos Emerald at will. Also, his tail is covered with spines, and can fire spines from his tail
Jak has learned parkour with Jay, and has learned Taijutsu from Espio, and to camouflage himself using his Chaos energy, he learned Guardian training from Knuckles, trained with Sonic for speed, Spin-Dash and Figure 8 technique, he trained with Shadow to learn to use Chaos Energy correctly, learned Mechanics and inventing from Tails and Rotor, and learned swordsmanship from Antoine D'cooletee.
Jak can be extremely negatively affected by Anarchy Beryl, due to being the opposite of the Chaos Emeralds, and he can be killed by the Chaos Siphon.