Milkshakes is Billy's pink cat. Milkshakes is not very detailed when drawn or recognized. She has pink fur and dotted black eyes, though a color is not specifiable. Whiskers do not seem to be heavily present, and no patterns appear on her fur. Milkshakes bares an adapted personality stereotypical of a cat, even when affected directly by supernatural powers or brain related powers. She has an aggressive activism towards Billy during most encounters, but can occasionally show a sign of feline affection for him. While Milkshakes is aggressive with Billy, usually it is for a good reason, or simply because she is annoyed with Billy. No definite interactions with outward characters, including Grim and Mandy, are seen as being present, or they are simply neutral. Unlike most animals in the franchise, Milkshakes is resistant to effects from supernatural entities. Having survived so many incidents involving Grim's initial blunt power from external sources, Milkshakes is best described as becoming slowly immune to such powers. Throughout the show, Milkshakes slowly showed less fluently visible attributes of being possessed by supernatural powers, or beings.