She is best friends with Billy and Grim. She is a devious girl from Endsville. In stark contrast to her cheerful, talkative, uniquely funny best friend Billy, she is shown to be grumpy, intelligent, quiet, bitter and utterly ruthless with no redeeming qualities whatsoever. Mandy is shown to be an anti-hero at best, and an antagonist at worst. An irredeemably cruel, spoiled, heartless, horrid, and unsympathetic little girl, she regards herself as being superior to many of the characters on the show, even her parents. She aspires to dominate the planet with an iron fist and to stay as far away from Irwin as possible. Mandy’s dreadful behavior has left her parents, Phillip and Claire, in fear and they are often shown avoiding her or bending to her will. Her mother spoils her rotten and showers her with money, compliments, and expensive gifts, despite her fears, and her father is stuck cooking and cleaning for her. However, it is shown that Mandy truly loves her family, as she was genuinely shocked when they revealed they were afraid of her. As much of a psychopath as she is, Mandy doesn’t like cheating and would rather accomplish things for herself. Mandy also has superior intelligence and strength not to be reckoned with. She has an almost superhuman force as she is able to battle monsters with ease as well as being able to understand complex theories of the world when referring to her superior intelligence, despite being a child, so she might be a prodigy. She also never misses a chance to exploit the stupid, which more or less justifies her attachment to Billy. While Billy gets himself/the trio into trouble, she is usually the one to get him/them out of it, along with Grim who, without her force, would not even bother trying to help. According to Billy and Grim, Mandy apparently has a fear of professional figure skaters--but she denies this, claiming that she simply "doesn't trust the way they spin," although, in Billy & Mandy's Big Boogey Adventure, her true worst fear is depicted as growing-up into a kind, chubby, unattractive old woman and settling-down with Irwin. It is also shown in the movie that Grim and Billy are actually very meaningful to her and she feels truly alone and lost without them. Even though Mandy is controlling, manipulative, wrathful, even devilish at times, she seems like an average little girl wearing a pink dress with a yellow flower in the center, black Mary Jane shoes, white socks (although they are barely visible at times), pale skin, and blonde hair accessorized with a black headband. Although she has black eyebrows that are thick and they are almost always furrowed and a frown to match which gives her a scowling expression most of the time, and her hair is curved into a style resembling devil horns. Billy has been Mandy's best friend since they were infants. Sadly, she considers Billy her idiotic henchman to do her every bidding as she never misses the chance to benefit from his astonishingly low IQ of -5. He usually complies and does everything she demands of him, seeming to either not mind and at times possibly even enjoy it. He rarely ever snaps at her for this, once, however, he did shout at her as a result of her treatment of him was when she had told him "Thank you". The other time was when he grew tired of her controlling behavior when she and her parents are forced to stay at Billy's house while their own home is being fumigated. Billy may be responsible for Irwin's crush on Mandy, since he flirted with her (in Mandy's body) in the episode Get Out of My Head! Mandy tends to be that of a tsundere towards Billy. Despite her negative, cruel behavior towards him, Mandy has been shown to care for Billy, and the feeling is mutual. Her feelings could be completely platonic since she mostly treats him nothing more than a servant. But Billy is the only person who Mandy allows to have physical contact with her, embracing her on numerous occasions, even kissing her on the lips a few times. Mandy has also been known to read Billy bedtime stories in the middle of the night when he couldn't sleep whether it be from eating nineteen boxes of cupcakes or other reasons. He has also suggested wanting to marry her at least three times. She also always helps Billy when he gets into trouble, that is until she becomes too bothered to continue and just stops or leaves the scene. In Billy & Mandy's Big Boogey Adventure, when Billy is supposedly eaten by a giant sea creature, she is in denial of his death saying, "Billy's always fine." But when he's been missing for six hours and Irwin's becoming restless; she starts to get worried herself as she gazes into the water and tears up, believing him to actually be dead. Moments later, Billy appears out of the water riding the Kraken, laughing and screaming "I'm fine!" Mandy gasps, pleased and surprised to see him again, but quickly denies ever being worried in the first place since of course, Billy is always fine. Near the end the main characters must face and conquer their worst fears. Mandy's worst fears are revealed to be her becoming fat, unattractive, jolly, and happily married to Irwin. It was in this movie that she realized that she can love another person besides herself, and it isn't necessarily a bad thing, and she faces her feelings toward either Billy or Irwin.