Rubella (Making Fiends)

Rubella is a fiend that Vendetta created to revenge Charlotte for giving her a musical greeting card. She then replaced Grudge as Vendetta's sidekick.

Why She's a Big Jerk to Grudge

 * 1) Like GG, she almost have ruined the Vendetta x Grudge relationship.
 * 2) She is a big jerk in the episode Rubella, where she throws Grudge into a pile of boxes in the classroom.
 * 3) Her voice (despite being decent) is somewhat very creepy and annoying.
 * 4) Her eating a table in one scene is very nauseating and destructive.
 * 5) She even helped Vendetta to throw away Charlotte in the water.
 * 6) Her name is also horrible, in fact she was originally wanted her named to be Mary, but Vendetta didn't like it. So she changed her name to Rubella (a type of virus infected in rashes).
 * 7) Worst, she even helped Vendetta to make fiends to scare and torture everyone in the town of Clamburg, as well as the school and the country fair in the episode "Concrete Shoes".

The Only Redeeming Quality

 * 1) At least Vendetta got rid of her, and befriended her hamster again in the Season Finale.