Steve Mannheim is a middle-aged human man with curly grey hair. He has wrinkles on his forehead, bags under his eyes, and stubble on his chin.
According to the model sheets, he is slightly more than 6 ft tall.
He wears a blue v-neck shirt, brown pants with white suspenders, and grey ankle height boots.
Not much is known about Steve. He, like the other dads, is very protective of Hollyhock and is a loving father. He does not like BoJack, but has good reason to feel that way.
He and the other dads sometimes communicate in a "Dad Speak" with the intention that people outside of the relationship (including Hollyhock) wouldn't be able to understand it.
However, unbeknownst to the dads, Hollyhock understands what they're saying perfectly well.
They live in Wichita, Kansas.
Steve and the other dads are mentioned numerous times throughout Season 4 by Hollyhock.
They make their first appearance in Lovin that cali lifestyle!!, when they travel to LA after Hollyhock accidentally overdoses on amphetamines (later found out to be caused by Beatrice putting weight loss supplements in Hollyhock's coffee).
They blame BoJack and refuse to let him see Hollyhock ever again.
In What Time Is It Right Now, BoJack travels to their home in Wichita, Kansas. After begging them to hear him out, he explains how he discovered he isn’t actually Hollyhock’s biological father—his father Butterscotch is.
He also found out Hollyhock's mother is his family's former maid, Henrietta Platchkey, and he wanted to give Hollyhock her phone number.
They agree to tell her, but still tell BoJack to leave.
The dads seem to have allowed Hollyhock and BoJack to talk again, as Hollyhock and BoJack continue to have a distant sibling relationship afterward. Hollyhock even visits him in Ancient History.
In Intermediate Scene Study w/ BoJack Horseman, Hollyhock mentions three of her fathers were disappointed that she quit when she quit rugby, while the other five were relieved to hear she quit the team it is unknown as to which fathers were relived and which were dissapointed.
- The Language (or "Dads Speak") of Hollyhock's fathers actually consists of adding "ittag" after every first letter in a word (i.e. "What do you guys think?", becomes "wittaghat dittago yittagou gittaguys tittaghink?") the language also doesn't seem to use the word "Is."