Pipevine Swallowtail caterpillar- Battus philenor- The Pipevine Swallowtail obtained its name from its primary food source the Pipevine Family plants. These plants have toxins in the leaves and this toxic diet makes the caterpillars poisonous to predators. Mature caterpillars are either bright red or purplish-black and about two inches long. There are two rows of fleshy bumps down the back with a long pair of filaments arising just behind the head and flaring out to the side. On purplish-black forms the bumps are either red or orange while on red forms the bumps are usually the same color as the body. The red on their bodies serves as a warning to hungry birds to stay away.