We’ve written about a cyclops shark, freshwater sharks, and whorl-toothed sharks, but we have to add a new curiosity to the digital curio: a two-headed shark. A fisherman working off the Florida Keys recently caught a bull shark, then opened it up to find that it contained two live fetuses, including one highly unusual one with two heads. The fishermen gave it to scientists, who wrote about it in an article published in the Journal of Fish Biology this week.