Take a trip to the east coast of Australia around March or April and you might run into one of these strange creatures. The caterpillar of the Tailed Emperor butterfly looks pretty normal—from the neck down. Its head, though, definitely secures it a spot on this list.From a broad, armor-plated forehead extend four bizarre horns that would be more at home on a dinosaur than anything from this millenium. The butterflies lay their eggs in groups, usually on Illawarra Flame trees, and the alien caterpillars emerge sometime around late March.