Martlet is a blue anthropomorphic bird-like monster with two wings used as arms. She wears two brown boots over her feet with a cotton trim. She has a mop of hair on top of her head with outsticking parts and a feather-like tuft near the back. She wears a greyish blue sleeveless shirt and dark blue pants. When Martlet transforms with her serum, her eyes turn a glowing yellow, and her hair, wings, and legs become longer. Her hair drapes down more and is more wavy.