The extreemly large green reptilian creature seen in the metroid games. He is usualy about 2 vertical screens tall and shoots large spikes from his stomach and thorns from his back/hands, depending on wich game. In the orrigional Metroid for the NES, he was only about 8 feet tall, as opposed to the stories-tall bohemoth of later games. He was to appear in Metroid Prime, but dude to time constrictions they cut him out.
Kraid is a generaly fun boss to battle in the metroid games.
He appeared in Metroid, Super Metroid, and Metroid Zero Mission.