Bratty and Catty (/ˈbræti/, /ˈkæti/) are a pair of vendors that can be found in an alley to the right of the MTT Resort. They are best friends, often saying the same lines or finishing sentences for each other (usually in the American valley-girl dialect), and both are big fans of Mettaton. They have several wares found from the Garbage Dump, including the Mystery Key.

Catty is a plump purple cat creature who wears a set of blue overalls with yellow buttons and tufts of yellow hair coming out from under it on either side. She has black hair with blue and lavender tips, and a yellow earring on her left ear. She, like Bratty, has a very heavy "stupid blonde stereotype" voice.