Marilyn

One of the three Shadow Sirens who seems to have no purpose except saying "Guh". If Beldam is the brains, Marilyn is definitely the brawn. She's big and incredibly stupid, but also very powerful, and is able to cast lightning bolts on her enemies. It seems that she can say (very few) other words, as evidenced when the Shadow Sirens annoice who they are.

Paper Mario 2 Stats

Boggly Woods Battle

HP 12, Attack 2, Defense 0
That's Marilyn. She's a Shadow Siren, Beldam's younger sister. She charges up her attacks occasionally. Says here she's the toughest of the sisters, so it might be best to defeat her first, huh?" Other than that, she doesn't have any particularly outstanding characteristics.

Palace of Shadow Battle

HP 40, Attack 7, Defense 0
That's Marilyn. She's Beldam's sister, another one of the Shadow Sirens. She'll attack you directly or use lightning. She also saves up energy for a big attack sometimes. So long as you avoid the brunt of her attacks, she shouldn't be too tough...