A heart was 'tattooed' on his arm. [=he had a tattoo of a heart on his arm]
a 'tattoo parlor' [=a place where people go to get tattoos]
He had a 'tattoo' of a heart on his shoulder.
(..) making our way up to the Monstrous Nightmare. But who'll win the honor of killing it? It's gonna be me. It's my destiny. See? Your mom let you get a tattoo? It's not a tattoo, it's a birthmark. OK, I've been stuck with you since birth, and that was never there before. Yes, it was. You've just never (..)2010 How to Train Your Dragon