From The TimeSplitters Wiki

Splitter Crow is the final form of Crow that you see. He is part human, part TimeSplitter, and part robot; it is the form that Crow thinks has made him invincible, which was his whole plan during the game. You first fight him twice, after the first time, he teleports before you finish him off. Then you fight him in the last level, Future Perfect, where you need to shoot out his hands and feet, and while he can't move or shoot you shoot at his buttocks. He is not playable due to his massive size. Unfortunetly they didnt make him smaller to be playable in arcade modes. An idea is if in co-op story mode get your friend to shoot his legs and feet while you shoot his buttocks with the ksmg rockets.