Monstrous growth

Fenrir

In Norse mythology, Fenrir is a monstrous wolf. He grows incessantly, destined to break free during Ragnarök to consume the sun.

Seps

legends describing it as capable of encircling entire mountains or valleys within its massive coils

Roc

casting vast shadows over the earth below and inspiring both wonder and terror in those who witness its flight

Draugr

In some tellings it can swell to an enormous size at will and grow heavier than several men, making its corpse difficult to move even after it is finally subdued.