Bojack Horseman is the titular protagonist of the series of the same name. He is a selfish and hate-filled jerk who has almost no friends and is hated by nearly everyone. He is voiced by Will Arnett.
Bojack is an anthropomorphic horse who lives in Los Angeles and suffered a harsh childhood, which resulted in him becoming a selfish and downright mean spirited maniac.
Bojack Horseman is a considerably troubled and hate-filled horse who has problems making friends with anyone. He also seems to be insecure to a degree most likely because of his childhood.