Steve Mannheim is one of Hollyhock's adoptive fathers.
Not a whole lot is known about him individually but like all of Hollyhock's fathers, he doesn't like BoJack but understandably so.
He is just trying to protect and take care of Hollyhock along with the rest of the dads and he is definitely a loving father.
He seems to be one of the more tempered and aggressive fathers when it comes to keeping BoJack away from Hollyhock for her own safety.
Steve Mannheim is a human man who appears to be middle aged, judging from his curly grey hair. He has wrinkles on his forehead, bags under his eyes and stubble on his chin.
He wears a blue v neck t-shirt and brown pants with white suspenders and grey ankle length boots.
According to the model sheets, he is slightly above 6ft. tall.