Halloween brings a focus on some strange and scary fish found underwater. For instance, the deep sea anglerfish uses a glowing lure to catch prey and has a unique mating behavior. The blobfish, often dubbed the world’s ugliest animal, appears very different under pressure deep in the ocean. Other odd creatures include the frilled shark, a primitive species dating back millions of years, and the goblin shark with its horrifying appearance. Many of these fish are harmless, yet their unusual looks can be alarming, especially for new divers exploring the deep sea.