Summoning the monster with an ancient toilet drain
While the monster is indeed dangerous, it can also prove very useful. Let's say there's a rival faction of people on the island and you want to take them out. Happily for you, the island's ancient Egyptian inhabitants created a way for you to summon the monster by… uh, by going into an underground chamber and unclogging a primitive toilet. Seriously, that's how it works.
Once this happens, you can simply hide out in the underground chamber until the monster crushes all of your foes.