Character: kumatetsu
Kumatetsu is a potential successor to the throne of the Beast Kingdom. He has to choose someone to be his apprentice and he ends up choosing a human boy named Ren (and later names him Kyuuta). He is rather tame most of the time, minding his own business and not interfering with anyone else's lives.
This tag implicates the_boy_and_the_beast (learn more).