A preserved cookiecutter shark on display during the Girls in Ocean Science Conference in California in 2016
Cookiecutter sharks are known for ripping small, cookie-shaped chunks out of sharks and whales much larger than themselves, but a new study has found they actually terrorise animals of all sizes. The green-eyed, alienesque sharks look like sinister sock puppets made of pastry dough and can grow up to 50 centimetres long. These odd creatures use their pointed teeth to feed off great white sharks ten times their size and are even known to nibble chunks out of human flesh.