The hippo's name is "The Slim" Which makes no sense but it stuck with him, he is Bertha's older brother who left the his family when he was 16 to pursue his dreams of being a pro wrestler like his father. Things didn't go to well for him in america so he went to Japan to hone his craft.

He couldn't be his sister growing up but he hasn't seen her in 7 years. Sio maybe things are different now.