Hickory Horned Devil
Citheronia regalis, the regal moth or royal walnut moth, is a North American moth in the family Saturniidae. The caterpillars are called hickory horned devils.
As the caterpillars age, they feed during the day. They molt four times. Each instar is different, but on their fifth and final instar they become a bright green color, with huge, black-tipped red horns, earning them their common name hickory horned devils.