Beaver Boss is a large beaver that is faced as a boss in the video-game "Fairytale Fights" - he is a bully who is introduced via him beating up a hapless lumberjack before being pummelled himself by the raft the player-controlled hero accidentally steers ontop of him.
This prompts Beaver Boss to go on the offensive and he attacks the hero via chewing on the raft, slamming his tail down in an attempt to crush the hero and finally flips the raft over in an attempt to devour the hero whole.
When finally defeated Beaver Boss seemingly meets a grisly end by smashing through a dam (somewhat ironically), falling to his death in the process - however the player-control hero is also taken on a wild ride down the waterfall as a result (but survives, of course).

However, it is revealed later on that Beaver Boss also survived the fall and the giant beaver resurfaces at the end of Chapter 3, chewing a tree down to form a bridge that allows access to the next area while also running off into the distance, causing a few lumberjacks to flee in the process. After pursuing him across the Wood Capital the player-controlled hero must face Beaver Boss in combat again after they accidentally ram into him a second time, landing once again on a floating piece of debris that acts like a platform.

This time round Beaver Boss attacks by repeatedly body-slamming the debris, swing his tail in an effort to dislodge the hero and a powerful roar.
After the second defeat, Beaver Boss finally meets his end in an even more grisly way than he did before, falling backwards into a shredding machine that proceeds to break apart, once again sending the hero plunging down a waterfall. He is then hooked in the eye by Father Giant, who was fishing, and is taken away and later seen dead, having been cooked by the Giant family as their meal.