The Black Beast of Aaaaargghh is a monster found in the satirical movie Monty Python and the Holy Grail. It is a legendary beast (which is ironically green-colored) who awaits and consumes any who enters the cave guarded by the Rabbit of Caerbannog, where the last words of Joseph of Arimathea can be found carved inside. Upon entrance, it devoured Brother Maynard and chased after King Arthur and his Knights of the Round Table.
As the horrendous black beast lunged forward, escape for Arthur seemed hopeless... when suddenly, the animator suffered a fatal heart attack. Upon such narration, the scene switched into an animator who keeled over and fell to the ground dead, and as Arthur escaped, the beast stopped and dissolved. The cartoon peril was no more. The quest for the Holy Grail could continue.