Wow, that's a great sculpin. Actually, it looks like a freshwater relative of the marine Great Sculpin, Myoxocephalus polyacanthocephalus. Most of the sculpins across North America, Asia, and Europe are all in the genus Cottus. But on several occasions marine sculpins, especially in the genus Myoxocephalus, have invaded large lakes and adapted entirely to freshwater. The giant, ancient Lake Baikal in Siberia has 15-20 species of sculpins that are found only there, a species flock.