The river spirit, Baggienik

The bagiennik is a chimera-type creature, which would be a mix between a fish, due to its elongated shape that gives it a hydrodynamic capacity when swimming, and a frog, due to its ability to breathe through the skin and of the lungs.
Its head is covered by a hardened leather casing that makes it quite resistant to shocks and various attacks. It also has a powerful jaw that allows it to grind and crush its food.
Its thin skin is made up of a series of glands that secrete an oily substance, capable of causing burns to its victims.
The bagiennik usually feeds on other small fish, which it usually catches by hiding part of its body at the bottom of the river or lake in which it is, leaving only its head exposed, which resembles a stone, so when the prey approaches and trusts, the bagiennik takes advantage and attacks.
They have two extremities like fins, when swimming, but that allow them to crawl when they surface.