It's a fake. You grab a battered dolphin skull and a hide of a musk ox, yak or similar hairy beast, dig a hole in your back yard, stuff the shit in and bury it for a couple months, dig it all up again, then arrange it all on a beach with some planks and other junk and hey presto! New unknown monster creature! Take some pictures and send them in to some crazy UFO nonsense site and write up some BS about special forces taking it all away, thus concealing all evidence... Mission accomplished!
Seriously tho, I haven't the faintest what it is. I can' imagine any sea-dwelling creature having long fur like that (monstrous drag), and such a mouth wouldn't work very well on land either. I can't imagine that thing chewing either plants or hunting animals with tiny little teeth like that, those are made to catch fish. Thus I can only conclude it has to be some kind of a fraud at work here.