Ike was originally sent to planet Earth 40 years before Goku was born, searching for a soul powerful enough to Copy. His race are the Argonians, with Argonians physology they can copy the genetic structure of one non-sentinent life form, and stay with it. This ability can only be activated once in an Argonian's lifetime. Without a body, they are of homo-sapien form but have no structure and can be destroyed as easily as a normal human. Argonians lifespan range from 450-600 years. Sent to Earth as an infant, he grew up in Berlin, had no friends or close contacts, and survived by stealing from others. When Goku was born, he felt a strong presence that had entered his world. He decided not to investigate it, the result of so many false alarms before. When Goku defeated Picolo in the last Tenachi Budokai, he decided to go investigate. This took him some time due to the nature of many humans being startled at his appearance without picking a form, and him having no money. At last, he managed to hijack a private plane off the boarder and head towards Goku. By the time he had arrived, Goku had just been killed by Picolo, sacrificing himself for Raditz. He decided not to reveal his form to the othess there. He was heading back when Bulma said that they could revive him with the DragonBalls, he stayed until he landed. He watched his fight with Vegeta, impressed. After Kai o' Ken x20, he took Goku's body and went away. He was linked to Goku, so whnverer Goku died, he did, and whenever Goku got stronger, the same applied. This was proved to be quite useful as he soon achieved the form of SS4. He confronted Goku after the Saiyan found all the Shadow Dragons. However, Goku proved to be too much for him, since he had trained and fought for so long and mastered full control over his form. However, with the kind soul that Goku is, he spared him. Ike walked away from the battle, vowing to one day get even stronger and take his revenge.
Ike looks like Goku, but with dilated pupils and red hair. He has red hair even in base form. He also most commonly wears a uniform that looks like the uniform based off of master Roshi's Tenachi uniform, except all symbols have been removed. This is what Goku wears from the Cell games till the end of DBZ. Ike wears a uniform exactly the same in all his appearances, except instead of a orange uniform with a blue undershirt, it is a red uniform with a black undershirt.
Ike: More than 20 yrs battle experience, all SSJ forms (SSJ1, 2, 3, -------10.) Goku's full power, of genius level intellect, all of Goku's techniques, (Kaio o' Ken, SS, levitating/flying....) can absorb energy by sending out invisible rays.