Suzy Johnson (Phineas and Ferb)

Suzy Johnson is a supporting antagonist of the Phineas and Ferb. She is the younger sister of Jeremy Johnson and archenemy of Candace Flynn, whom she despises because she doesn't want other girls around Jeremy other than herself.

Why She's Loathsome

 * 1) She is very manipulative, deceitful, overbearing, devious, sociopathic, dominant, spoiled and bratty control freak towards her brother Jeremy.
 * 2) Her facial expressions look very uncanny, ugly and creepy, especially when she smiles sadistically.
 * 3) Her personality is similar to a stereotypical yandere as she is unhealthily obsessed with Jeremy except the fact that a yandere is obsessed over his/her love interest, while he is her brother.
 * 4) She torments and terrorizes Buford and Candace for no proper reason (although Buford may have bullied her or Jeremy).
 * 5) She's one of the only bad characters on an otherwise good show besides Mr. And Mrs. Doofenshmirtz.
 * 6) While Candace is often the antagonist, she's neither evil nor truly spiteful - only impulsive and a bit high-strung, and has shown on occasion that she genuinely cares for her brothers.
 * 7) Even the main antagonist, Doofenshmirtz is quite Affably Evil, loves his daughter dearly, and is an absurdly Friendly Enemy to Perry. His attempts to take over the ENTIRE! TRI-STATE! AREA! come across as more pretending to be evil to get attention than the evil acts of a power-mad lunatic.
 * 8) Meanwhile, Suzy is just spoiled brat who isn't even an evil antagonist. She doesn't have sympathetic motives or reasons to be antagonistic or has tragic backstory unlike aforementioned characters, making her even more unlikable.
 * 9) She never got punishment and comeuppances for her actions, not even in later episodes, this makes her a Karma Houdini. Even worse, her parents and neighbors think that she's just a cute little innocent girl.
 * 10) Although It is understandable that it is common that a younger sibling to become so attached to their brother or sister that they are afraid of any possibility of separation from them, But it doesn't excuse the fact that she's badly written. She doesn't even have a reason to mistreat because Candace is innocent as she doesn't do anything do to Jeremy.
 * 11) She was at her worst in "Comet Kermillion" and she did these horrible things mentioned down below and stood out as Karma Houdini as nothing bad happened to her in the end of the episode.
 * 12) Suzy took a nut from an elderly woman and sent it flying into Candace's pants as Jeremy went away briefly. Squirrels then went after the nut and into Candace's pants, causing her to go off freaking out.
 * 13) While stopping for ice cream, Suzy caused Candace to slip and fly into the ice cream vendor's cart and down a set of stairs. She then scared Candace off by putting a squirrel in her face.

Redeeming Qualities

 * 1) Even it is not seen on screen or mentioned but It is hinted that she makes peace with Candace when she grows up as Candace is seems to be happily married to Jeremy in future.
 * 2) Although it's extremely rare and only when her brother isn't around, she sometimes is nice to and helps Candace as seen in "Suddenly Suzy".