Scientists found this strange creature at the Great Barrier Reef's Lizard Island and named it, aptly, the Christmas tree worm. The spiral "branches" are actually the worm's breathing and feeding apparatuses, while the worm itself lives in a tube. These tree-like crowns are covered in hair-like appendages called radioles. These are used for breathing and catching prey, but they can be withdrawn if the Christmas tree worm feels threatened.