It wasn't the first time
the Imp threatened Joffrey.
Game of Thrones Season 4, Episode 6
Speak, Imp.
Game of Thrones Season 1, Episode 6
the Imp rounded on him.
Game of Thrones Season 4, Episode 6
Dwarf? You should have stopped at IMP.
Game of Thrones Season 2, Episode 2
I'll not have my honor questioned by an IMP!
Game of Thrones Season 2, Episode 2