Duchess (Foster's Home for Imaginary Friends)

Her Royal Duchess Diamond Persnickety, the First, Last and Only or simply Duchess (referred to by her full name in the pilot movie) is an imaginary friend and the main antagonist of the series Foster's Home for Imaginary Friends. She speaks with a German accent and is voiced by Grey DeLisle.

Why She Intentionally Sucks

 * 1) This imaginary friend is a scheming, snobby, pompous, stuck-up, vain, conceited, negative, extremely rude, short-tempered, arrogant, selfish, self-centered, and mean Picasso-like pain in the neck who makes Bloo look like a saint by comparison and is actually two-dimensional when she turns her head or body (except in "House of Bloos").
 * 2) She dislikes everyone at Foster's and is disliked by everyone there as well.
 * 3) She always forces the house residents to do everything for her, even get her out of bed, since she doesn't do it herself. This proves how very lazy Duchess is.
 * 4) She is really hideous in appearance as mentioned by the other characters in the show.
 * 5) She barely gets punished for her actions. Note that her punishment in the pilot movie was that she was forced to stay at Foster's when she should’ve been kicked out of the house and sent to jail.
 * 6) Despite her desire to leave, Duchess insults almost everyone who tries to adopt her except for the rich family in the pilot showing that while she badly wants to leave she doesn't want to live in any less pampered lifestyle she would be forced to give up if she went home with a normal family (in other words, she wants to be adopted by a rich family).
 * 7) She has teamed up with Mac's brother Terrence, particularly in the pilot movie.
 * 8) She gets absolutely no character development and basically remains stuck-up, annoying, and cruel for the entire series.
 * 9) The episode "Duchess of Wails" is her biggest role and arguably her most intolerable appearance considering how Mac and Bloo are forced to put up with her.
 * 10) She could easily be removed from the show without much changing (aside from the episode mentioned above). Goes to show how her only real purpose is being a load for the rest of the cast.

Redeeming Qualities

 * 1) She at least did make some good points in the show at times, such as in the episode "Partying is Such Sweet Soiree".
 * 2) Despite her hideous appearance, she has a unique Pablo Picasso-inspired character design.
 * 3) Making her unlikeable was likely intentional, and she arguably serves as a good antagonist in the episodes she appears in.
 * 4) There are also times when she can be tolerable or even funny.
 * 5) Grey Griffin does an awesome job voicing her.