The hickory horned devil is among the largest of our native saturniid caterpillars. It is 12.5 to 14 cm in length – about the size of a hot dog. The caterpillars vary slightly in color, but are commonly blue-green. The second and third thoracic segments each bear two long and two shorter orange, black-tipped scoli (tubercles in the form of spinose projections of the body wall). The abdominal segments each have four short, black scoli, and segments 2 through 8 have a pale, oblique lateral stripe. Although the larva has a fierce appearance, it is harmless, and becomes a beautiful regal moth. View the regal moth here!