The doommushoom girls are group of young girls who are friends and work for Boswer Jr. They are not really sucessful in their jobs, which makes both Boswer and the koopalings think their a mistake of hiring. They are all powerless, but three of them are superhumans with power. They debuted in Super Mario Apprentice . Usually in games, when Boswer has his minions defeated in four stages, Boswer Jr. requested they attack but Boswer then tells him not to talk about or even send "those failures".
- Kassandra - leader and self-titled "killer chef", has a huge crush on Boswer Jr. (who likes her back), she shows to be the most creative of them all.
- Layne - self-titled "sandstorm maker", most of her friends are moles or desert beings, she is also the oldest of girls.
- Marina - self-titled "ocean archer", a vain mermaid that uses a clam for dodging attacks.
- Florissa - self titled "predator charmer", use magic to use plants as weapons and defense, has a crush on Roy (who also likes her back).
- Grace - self titled "ballerina of despair", youngest of the girls, passionate dance fighter, has a big crush on Larry (who also likes her back), very artistic.
- Cici - self titled "pink cowgirl", a reckless western-styled girl, normally lassos heroes.
- Ubara - sel titled "flying rascal", a human girl with wings like a koopa paratroopa, has a crush on Morton (who likes her back).
- Nikki - self titled "blue butterfly".