Amanda, better known by her superhero alias Monster Girl, is a major character in Invincible, debuting from Season 1 and onwards. Originally referred to as Monster Woman, she emerges as an essential member of the new Guardians of the Globe after the massacre of the original team by Omni-Man. Amanda has the capability to change into a formidable, massive creature, significantly enhancing her power and resilience. Yet, this change carries a distinct curse; every time she employs her abilities, her physical form regresses in age, making her look like a young girl even though she is 26 years of age. Once Robot's scientific technology healed her curse, she started to develop feelings for him and their romance blossomed.