Butterfly caterpillars come in different shapes, sizes, and colors depending on the species. Generally, they have segmented bodies with soft, plump, and elongated shapes. They have three pairs of short legs and several pairs of fleshy legs on the abdomen. Most of them have distinctive markings such as stripes, dots, or spines on their bodies to help them camouflage or warn predators of their toxicity. Some species also have hair-like structures called setae that help protect them from predators and parasites. As they grow, they shed their outer skin and molt into a new, larger one until they reach full size and are ready to form a pupa or chrysalis.