Meet 'Mad Hatterpillar,' the caterpillar that uses its old heads for defense

Photos: Invertebrates: 8 of the weirdest spineless creatures
The ocean ambush predator – The Bobbitt worm or sand striker (Eunice aphroditois) is an aquatic predatory bristle worm that ranges from 4 inches to 10 feet long and dwells in burrows it creates in the ocean floor. It lives mainly in the Pacific Ocean but can also be found in the Indo-Pacific ocean area.
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Photos: Invertebrates: 8 of the weirdest spineless creatures
An unusually beefy beetle – Native to Africa's tropical forests, giant or Goliath beetles (Goliathus giganteus) are among the largest insects. They only range from 2 to 4.3 inches long, but they can weigh up to 3.5 ounces — that's nearly as heavy as a baseball.
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Photos: Invertebrates: 8 of the weirdest spineless creatures
The moth with map-like wings – The atlas moth (Attacus atlas) is a large moth native to the forests of Asia. Its wingspan measures up to 9.4 inches. Since the moth has no mouth, it doesn't eat once it has emerged from the cocoon — shaving days off its only one- to two-week life span.
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Photos: Invertebrates: 8 of the weirdest spineless creatures
The giant deep-sea scavenger – Bathynomus giganteus is a species of aquatic crustacean and a member of giant isopods. This isopod resides in cold waters in the West Atlantic, and its large size has been attributed to deep-sea gigantism — when invertebrates living in cold, deep waters grow larger and have longer life spans.
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Photos: Invertebrates: 8 of the weirdest spineless creatures
Watch your food around this giant crab – The coconut crab, an iconic animal of the Batanes islands in Philippines, can weigh up to 9 pounds and grow up to more than 3 feet in length. Since the coconut crab will eat anything left unattended on the ground, it's also known as the robber crab or palm thief.
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Photos: Invertebrates: 8 of the weirdest spineless creatures
An elusive giant cricket – Native to New Zealand, the giant wētā (Deinacrida tibiospina) is a member of families of giant flightless crickets. The species name of these wingless creatures translates to "tibia spine" or "shin spine" — likely a reference to its spiny hind legs.
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