Nemesis, (full name, Nemesister), is the main antagonist of the Foster's Home for Imaginary Friends episode "Challenge of the Superfriends" and was created in a situation involving Brother and Sister rivalry of her owner.

She is voiced by Grey DeLisle.


Nemesis is the opposite to Imaginary Man, as she has a contrast in personality. Her main goal is to conquer the world by placing feminine objects around the world and let only girls to have rights. She seems to be determined, yet cocky when it comes to battling and is more calm when she is at her lair. She is also easily angered, as seen when Uniscorn (Bloo) betrayed her when in the Laundry room.


Nemesis wears a short, black, strapless mini dress with white frills at the bottom and a pink chain belt with a giant heart on it (possibly a purse). Her hair is very poofy and is a slightly darker pink then her skin and it has a small white bow in it, her eyes are light blue with no pupils, she also wears thigh high black boots and black gloves that go up to her sholders.


Nemesis has five parts of her body shaped like hearts:

  • Her hair.
  • Her head.
  • Her upper body.
  • Her belt on her dress.
  • Her boots.


Nemesis has a few notable abilities as seen in the episode, these include:

  • Blasting a shower of roses at her opponent.
  • Creating items associated with younger girls, including rainbows.
  • Levitating


  • Her hair and skin are similar to Gwen's anadite form from "Ben 10."