Butatsch

This horrific creature resembles an enormous, deflated cow’s stomach, studded with thousands of glaring eyes awash with flame.
The Horror in the Lake. In certain deep, still lakes located in secluded valleys and mountain glens there lives the butatsch, a terrible monster from the subterranean reaches of the earth. It occasionally rises from the deep underwater caves in which it lives to slaughter and devour any creature that comes within its reach. The butatsch’s amorphous body is easily as big as an elephant, and its countless eyes are frightening to behold. The butatsch burns or melts organic material before absorbing it and leaves nothing behind when it has finished eating.
Unsettling Morality. While the butatsch leaves a path of destruction wherever it goes, it is driven by a bizarre morality. It has been known to ignore and even protect weak or defenseless targets, such as farmers and cowherds, against other monsters and humanoids, slaughtering the weaker creatures’ persecutors before vanishing back into the lake from which it came.