MARTLET is one of the few Monsters left in the Underground due to a human killing almost everyone. She fled twice from them, fighting them once and giving them a chance to change their ways. Now she's transformed into a more powerful version of her original self after injecting herself with Chujin's serum in hopes of becoming powerful enough to defeat the human who's been genociding Monsterkind. She's a large anthropomorphic bird and is very strong as well as durable. Monsterkind's final hope.