From Monkey Island wiki
The Jungle Beast of Flotsam Island lives deep within the jungles and is never seen. Only Hemlock McGee seems to believe in it, and his depiction of it hangs in Club 41. He tells the story of how meaty sacrifices are left on the altar in the jungle at night and disappear before the morning, with a foul stench left behind.
Guybrush Threepwood can track the monster by dousing his offering in sugar water, leaving a trail of fireflies for him to follow. The beast turns out to be a meat-eating plant. Guybrush can retrieve a lion's paw from its mouth; it retains the beast's terrible smell and is an ingredient in the "Feast for the Senses" used to embiggen La Esponja Grande.