In the second episode of Season 4, scenes from the early life of BoJack’s mother, Beatrice (Wendie Malick) — a melancholy tale of loss, guilt and mental illness — unfolded in flashbacks. Her story continued in the season’s emotional penultimate episode, “Time’s Arrow,” which recounted her history with BoJack’s dad, Butterscotch Horseman (also voiced by Arnett), whom she married over her own father’s objections. Young BoJack bore the brunt of the animosity that developed between Beatrice and Butterscotch. Decades later, as the marriage continued to deteriorate, Butterscotch impregnated the family’s maid, Henrietta Platchkey (Majandra Delfino), and Beatrice persuaded her to give up the baby for adoption.
Unbeknown to BoJack, that child turned out to be Hollyhock Manheim-Mannheim-Guerrero-Robinson-Zilberschlag-Hsung-Fonzerelli-McQuack (Aparna Nancherla), who got her extraordinarily long last name from her eight gay, polyamorous, adoptive dads. After a lifetime of being told she looked like BoJack Horseman, Hollyhock comes to Los Angeles from Wichita, Kan., in hopes of finding out whether he is her biological father. A DNA test confirms that they are related, and she moves in with BoJack and begins searching for mother.
In his efforts to be a good parent to Hollyhock, he takes her to meet Beatrice, now languishing and suffering from dementia, in a Santa Barbara nursing home. Eventually, they bring Beatrice to live in BoJack’s house — an arrangement that ends in disaster when Beatrice starts spiking poor Hollyhock’s coffee with weight-loss drugs, and the girl ends up in the hospital. When he realizes that his mother was to blame for Hollyhock’s brush with death, BoJack gives up on the old lady for good, delivering her to the worst nursing home he can find.
Once Hollyhock recovers, the eight gay dads whisk her back home to Kansas. But in the Season 4 finale, it becomes clear to BoJack that he isn’t her father — he’s her half brother. And in a grand gesture of fraternal love, he flies to Wichita in order to connect Hollyhock with her mother, Henrietta. The last time we see Hollyhock, she is on her way to meet her birth mother in Minneapolis.