
Sheldon, you can't train my girlfriend
like a lab RAT.
The Big Bang Theory Season 3, Episode 3

The difference between us and the RAT...
The Big Bang Theory Season 1, Episode 5

So, I'm like a lab RAT
before your real friends come over?
The Big Bang Theory Season 10, Episode 6

Getting his pet RAT a reward
Game of Thrones Season 3, Episode 7

a snitch, a filthy RAT.
Money Heist Season 1, Episode 6