Vampire Ambassador

The Vampire Ambassador is exactly what the title promises: a formal diplomatic envoy who also happens to be an undead bloodsucker, treated by everyone around him with the same bureaucratic shrug given to any other alien dignitary. He shows up in official capacities, speaks with stiff diplomatic courtesy, and never once acknowledges the absurdity of his own existence.

The joke is entirely in the deadpan collision of genres — gothic horror filtered through the dullest possible register of interstellar politics. Maurice LaMarche gives him a plummy, self-important formality that never winks at the audience, which is exactly why it lands; the character stays funny because he refuses to notice he's funny.