It's a monkfish. They look terrible, but taste good. Their meat is similar to lobster in both taste and texture, and you can find them on the menu at many seafood restaurants. They're an anglerfish -- one of the group of fish which dangles a natural "lure" over the top of its head and in front of its mouth, and then when a curious fish comes to check out the "bait", it gets sucked into that giant mouth.
