Uncle Pyko is a very intelligent toymaker who worked for Judson Jakes's company Mayhem Mekaniks. He is the main toymaker and also the creator of Judson's killer robots - the Psycho Circus.
Pyko stole the sacred text of the Loonies of Halfworld, long undecipherable to any who had read it. He learned the true story of how the Loonies, the robots and the animals came to be on Halfworld. Pyko turned on Judson and joined forces with Rocket Raccoon and his allies. Together, Pyko brought them before the robots of Halfword who created toys capable of curing the Loonies from their insanity, thus helping to end the Toy War between his former employer and Lord Dyvyne.
Pyko left the planet with Rocket and his team along with the robots of Halfworld.