Gabby the Mime

The Mime came with The Sims expansion, "House Party". Whenever you throw a Party and it was a bad one i.e. the party, the mime will come and like the Tragic Clown, will try to make the guests happier but will end up making things more worst than it was before. You can slap him but to no effect, the only way to get rid of him is, make everyone happier, end the party, or cheat by using the move_objects on cheat mode and delete him.

Note
It has been rumored that the mime will return in The Sims 3.