You have to take the cryptozoology class and in that class the teacher will ask you if you want to learn more about a mythological creature, you have to choose the option "bugbear". And then in one of your classes, he'll randomly appear and you get a chance to ask him questions about himself, you have to get 10 strength so you could ask him about his smile, if you'd done both of that i think you'll be able to get his good end! (although his good end doesn't really seem like its good ahaha...)