With 750 legs, the millipede Illacme plenipes is the leggiest animal on Earth. Once believed extinct, scientists rediscovered the species in 2005 — more than 80 years after it was first described. This exceedingly rare millipede is known from a single 4.5 km2 area in California, and the millipede has a beautifully intricate anatomy including the ability to spin silk from long hairs covering its back.