Princess Mandie is Mark's terrifying former fianceé; a barbaric extraterrestrial princess who can perhaps be best described as psychotically violent. Antagonized by Mark's intimidation about her and his refusal to marry her, Mandie constantly plots revengeful, bloodthirsty murder against him and he often seeks Timmy's assistance in providing shelter from the princess's deadly ways. As a running gag, many regard Mandie as physically attractive (most notably Cosmo, who often must poorly-disguise his slight infatuation for Mandie from his wife) with the exception of Mark Chang himself, due to the reversed order of Yugopotamians' views on attractiveness. Princess Mandie is extraordinarily dangerous, destructive, and hostile, going so far as to swing axes at people who mispronounce her name (the "correct" pronunciation is Man-DIE, instead of Mandy), and the only reasons provided for her desire for Mark's hand in marriage is her lust for power, which she may gain after wedding Mark and being hailed as queen of Yugopotamia. In an episode, Vicky fought with her and Vicky won. Mandie was arrested in Yugopotamia.