Half-Man, Half-Bull? Surely you’re joking. But if it’s Dungeon Crawling you need to do there’s nobody better than The Minotaurs.
When someone befriends an animal, s/he obtains the ability to unite their souls together and take on the form of that animal as well as its abilities. S/he also gain some properties of that animal even when they are no keener t transformed, such as resistence to cold or senses. If s/he really wants to s/he can half transforms taking on characteristics of the animal and their normal form