
finds proof of ALIEN life.'
The Big Bang Theory Season 12, Episode 20

...he's allergic to Earth nuts,
but I'm the ALIEN.
The Big Bang Theory Season 8, Episode 21

He was only pretending to be scared to trick the ALIEN king.
The Big Bang Theory Season 12, Episode 18

They exist in case we ever make contact
with an ALIEN civilization.
The Big Bang Theory Season 9, Episode 10

No ALIEN lady ever told Captain Kirk,
"Hey, get your thing out of my nose."
The Big Bang Theory Season 1, Episode 13