Muffet is the leading baker in the underground. Her sweets can't be beat and are unmatched throughout the underground! She works alongside Grillby, maintaining the resteraunt when Grillby is out doing field work for Sans. Muffet gives off a sweet demeanor, but can often be manipulative and clever and can be quick to comment back at her friends with hilariously snarky comments. She's good friends with Mettaton, Grillby and Napstablook, Mettaton even letting Muffet have a baking show for the Underground to view. 

Muffet can utilize her soul into a Whip. She can use this defensively and offensively. She'll mostly work to distract her enemies before entrapping them in her web, but if needed to dispatch the enemy herself, she's efficient with her whip and can leave serious lacerations on her foes. She'll call upon the power of her pet when shes in a cinch, buying her enough time to recover and bounce back into the battle

(I don't have a real headcannon voice for Muffet, so have some fun with her. Though you'll get bonus points if you can utilize some sort of british or english accent uwu)