Sewaddle is a caterpillar-like Pokémon with a big leaf growing around its head. The leaf starts at the back of its neck and grows forward, surrounding the head from the sides. The leaf also has several holes in it, as if it was bitten by an insect. Sewaddle's head is a perfect sphere in a pale shade of yellow, and on the top of it there is a small feature divided into two ball-like parts. Its snout is half-moon shaped with two small teeth pointing downwards, and the lower part of the head is white. Sewaddle's body is green and consits of a single piece, but a number of lines along the body suggests that it is segmented after all. It has six orange feet, which similarly to those of Weedle are simple spheres.