Wumpus, q, is a reference to the old game called Hunt the Wumpus. It is a strong animal that can cling to ceilings. It is a rather rare creature but not among the rarest. Should you ascend a game, you are pretty much guaranteed to meet at least a few wumpi.
Encyclopedia entry Edit
The Wumpus, by the way, is not bothered by the hazards since
he has sucker feet and is too big for a bat to lift. If you
try to shoot him and miss, there's also a chance that he'll
up and move himself into another cave, though by nature the
Wumpus is a sedentary creature.