The Wrestler star has long loved Chihuahuas and regularly takes in new mutts from a rescue centre.
He was once the proud owner of seven of the dogs, but he reveals to British TV host Alan Carr: "I'm down to one."
And Rourke admits he almost didn't end up with little Jaws, after the pooch bit him during their first meeting at a shelter: "(The owner) said, 'Oh no, you don't want that one... we're putting him to sleep.' He's growling and spitting and I say, 'It's ok, it's ok'.
"I went to give him a kiss and he bit me here (above lip). I got two stitches. They think I'm going to sue them... I'm a little embarrassed cos the dog was (small) but it really hurt a lot. About a half hour later I said, 'I'll take him'.
"I've had him for five years now. I can pick him up - it took me six months to be able to pick him up. He's not the friendliest thing on the planet."