As much of a psychopath as she is, Mandy doesn’t like cheating and would rather accomplish things for herself. However, it is shown that Mandy truly loves her family, as she was genuinely shocked when they revealed they were afraid of her. 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.

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. She aspires to dominate the planet with an iron fist and to stay as far away from Irwin as possible. 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. Mandy is shown to be an anti-hero at best, and an antagonist at worst. In the episode Sickly Sweet, Mandy turns into a monster with the combination of Hippopotamus, Alligator, Bear, and Iguana by 'The Mask of Beast' for her cynical attitude with Billy and Grim. However, the kids won after Mandy cheated in the limbo contest and Grim has been stuck with them since. Snuggles and Billy, but if the kids won Grim had to be their best friend forever. If Grim beat them in a game of limbo, he could have Mr. Grim had appeared to reap the soul of the hamster as it was time for the hamster “to kick the bucket” as Mandy had said earlier in the episode, but neither the hamster nor the duo would give in.

Years later, she and Billy had met Grim on the day of the tenth birthday of Billy’s pet hamster, Mr. He simply giggled in response to this, telling 'she digs me', thinking that she liked him. She punched him, called him a creep, and slammed the door in his face. When she did, he immediately pointed out that she had no nose and shoved an ice cream cone into her face after she had asked him if he was 'some kinda idiot?'. Later, Billy stole her feeding bottle, put it in his mouth and began flushing it like a toilet. In the episode The Problem with Billy, it was shown that she first met her best friend Billy at an early age, when Billy had repeatedly rung her doorbell until she was annoyed enough to answer. However, she had to smile in front of everybody in the school auditorium when she sang Over the Rainbow as part of a pageant. However, this did not apply in some earlier episodes, where she smiled only to her friends Billy and Grim. When she does smile, it throws off the natural order of the universe as seen in one episode, 'My Fair Mandy'. When Mandy was a baby, she was shown to have never smiled she was even visibly unhappy in her mother’s womb.

Buttercup song billy and mandy