I had to double check the calendar when I first saw this gem in the AIX online documentation yesterday, but it was still March, not yet April first.
AIX 6.1 information > Commands > Categorical list of commands
Purpose: Starts the hunt the wumpus game.
Description: A wumpus is a creature living in a cave with many rooms interconnected by tunnels. You move among the rooms trying to shoot the wumpus with an arrow and trying to avoid being eaten by the wumpus or falling into bottomless pits.
As far as I can tell, this command is a hand-me-down from when the System V UNIX-based AIX incorporated bits from BSD.
I suppose this and the other games are still there for those customers using AIX on workstations (rather than bored sysadmins monitoring high-end servers… I hope).