This is Not a Snake, It’s Some of the Best Mimicry We’ve Ever Seen Dynastor darius darius is an odd looking caterpillar. Its long green body is punctuated by a distinctly black head covered with hairs exploding like miniature fireworks. But when these caterpillars enter their pupal stage — when the insects craft chrysalises to become butterflies in — the odd look becomes instantly familiar. As D.