Arthropod

World's Largest Arthropod
Hail Crabzilla! The Japanese Spider Crab is the biggest arthropod on Earth--their legs are believed to grow up to 12 feet long. But since they live at such great depths (typically 1,000 feet down or so) a full grown spider crab has yet to be caught. So for now, we'll have to make due with the 5 foot long Crabzilla, one of the largest known crabs in the planet.