From PathfinderWiki
Race/Species Hydra
Gender None
Homeland Sevenarches, River Kingdoms

Source: Mythical Monsters Revisited, pg(s). 31

Ladonica is a legendary hydra that lives in the well-watered woodlands of the River Kingdoms. The beast is enchanted with powerful fey energies after it accidentally stumbled upon a gateway to the First World in the heart of Wilewood in Sevenarches. Those who seek out Ladonica, either come back empty handed or are never heard from again.[1]