A bunch of cranky, thieving dwarves (among them Randall, Fidgit, Strutter, Og, Wally, and Vermin).
They were once employed by the Supreme Being to fix the holes in the fabric of spacetime, but then decided to use those holes to steal unimaginable riches. Well, you would, wouldn't you?
"Heroes! Heroes! What do they know about a day's work?"