Monster

The monster is a monster(I guess) from the planet Earth in (series).

Goal
They're goal is to ruin the Fishpeople's lives anyway they can, because the Fishpeople took thier home and claimed it as their own, but the Fishpeople didn't know that. The monsters were the villians because they didn't tell the Fishpeople that and broke the power source that powers the underwater cave.

Appearances

 * Fishpeople or Peoplefish?