That is clearly a lava shark. Shark lava would be the result of stuffing a volcano with sharks until it explodes. This has been my TED talk, thank you.

That's because you assumed is a Shark made of lava, but is actually Lava that got in the shape of a Shark, also know as the classic variation of lava know as "Shark Lava".
Well I hope you enjoyed this gameplay, give like and subscribe for more content, it helps a lot, and I see you in the next video, byebye.