What is the term for an unintelligent being?

Kinda like the opposite of extraterrestrial. i searched up the opposite of extraterrestrial and found that it is terrestrial. but when i search up the definition of terrestrail, it isnt an unintelligent being. and i found intraterrestrial on a yahoo answers question, but i couldnt even find out what it meant when i searched it on google. so now i am trying to figure out what an unintelligent being is called. a creature or living being that isnt extraterrestrial. has no intelligence. kinda like bacteria or something. thanks to everyone who answers