in the beginings they were defined as humans until satanist mixed some of them with gorillas. new definition for gorilla mixed
gorilla - a person who treats others violently and roughly, especially for hire:
hoodlum, ruffian, thug, tough, informal hooligan, slang goon, hood, see attack/defend, crimes. see thesaurus.
http://www.answers.com/topic/gorilla?method=6