Brughadatch

The biggest difference between a gahlepod and a grown brughadatch isn't their humanoid appearance, but the powerful magic they gain as they mature.

Brughadatches are malevolent fey tricksters with distinct stages of life: they spawn from the First World's primal energies as esurient tadpoles, grow into humanoids capable of creating enticing illusions, then finally evolve into huge, slothful toads that warp their environs with mere thoughts.