A superior, non-human entity of natural or supernatural origin that is indigenous to planet Earth.
UFO's, fairies and elves are believed by some paranormal researchers to be Ultraterrestrials.
A being from another dimension or plane of reality
- It doesn't make any sense, how can they summon those demon-monsters from thin air in Buffy the Vampire Slayer?
- Well, I guess they are some kind of Ultraterrestrial entities that pop in from another dimension...