It looks like a caterpillar but a class of butterfly. This caterpillar knows as Euthalia Aconthea. Euthalia aconthea, the common baron, often called simply baron, is a medium-sized nymphalid butterfly native to Sri Lanka, India, and Southeast Asia. It flies with stiff wing beats and often glides This body structure helps it to protect itself from its predators. If you see it suddenly on leave get confused and notice only leaf without anything presence.