Some rare crabs, according to Thailand’s Department of National Parks, Wildlife and Plant Conservation. CREDIT: Department of National Parks, Wildlife and Plant Conservation via Facebook. Panda crabs (Lepidothelphusa cognetti) are semi-terrestrial crabs named for their (usually) panda-like black and white patterns. While there isn’t too much data about panda crabs yet, much less the purple variety, one thing is certain—the pictures are fantastic. Earlier this month, Kaeng Krachan National Park also celebrated finding a specimen of the more traditional black-and-white version.