Abner Horowitz is a character from the Grand Theft Auto series who is mentioned on the Grand Theft Auto: Vice City Stories website. Horowitz is the leading surgeon in Vice City at the Ocean View Hospital, specialising in sex change operations, and by 1984 specialising in the ability to change a person into both a man and a woman. Doctor Horowitz conducts Reni Wassulmaier's fourth sex change operation.
- From the official GTA Vice City Stories website:
Horowitz: "What we're offering is something new - a chance to be both a man and a woman, both at the same time."
- From the mission So Long Schlong:
Reni Wassulmaier: "So, now I must go to Dr. Horowitz. He's a genius. Tomorrow, new Reni!"