Zero

Zero, a very anxious and shy briareon.

Born in a Shiny mill. Sold to the highest bidder barely after he  hatched. Highest bidders were rich parents who wanted their son to have a  special Pokemon partner. The twelve year old was arrogant, and did not  respect Zero. He pushed Zero much too hard when battling, taking  advantage of Zero's hatred of him to give him a very powerful  Frustration move. Zero evolved when he had had enough, and ran away at  level 20.
Zero was later adopted by some Team Skull grunts after having a hard  time as a Shiny wild Pokemon, with many Trainers attempting to catch him  against his will. The grunt group were just kind to Zero and left food  out for him, despite his hostility and fear of humans. They slowly gained the skittish pokemon's trust, eventually becoming  such good friends with Zero that he became their mascot. Zero doesn't  have a ball, and cannot be forced to fight any more. (Any Team Skull  hopefuls who eye Zero with a little too much interest, or who express  the desire to catch him, get turned away.)
Zero now lives happily as a Team Skull mascot, not in a ball or owned by any one member of the team. He likes sunning near the beach, playing with other Shiny Pokemon,  stealing human food from bemused and annoyed Team Skulls, and riding on  the tallest Team Skull's shoulders. When not stressed by unfamiliar people and Pokemon, he's quite  affectionate and gentle. Also a huge prankster; food-stealing,  paint-dumping, tripping into mud puddles and surprise attacks are his  favorite pranks.