Behold the mightiest attack frog known to man. Thank goodness it lived 65 million to 70 million years ago. A U.S.-led team spent 15 years assembling a nearly complete skeleton of Beelzebufo ampinga—"armored devil frog"—a 10-pound, 16-inch (five-kilogram, 41-centimeter) beast that heaved across what is now Madagascar. Equipped with a bony head shield, wide mouth and powerful jaws, researchers speculate that Beelzebufo (shown here in an artist's rendering) may have been capable of slaying small vertebrates such as lizards and hatchling dinosaurs. In girth, the animal surpasses the 13-inch (33-centimeter) goliath frog of West Africa, the reigning heavyweight frog champ at seven pounds (three kilograms), and may have been the largest frog ever. Its existence also bolsters the notion that Madagascar and South America were linked during the Cretaceous period, perhaps by Antarctica: The armored amphibian is closely related to a group of aggressive South American hoppers known as "Pac-Man frogs" for their large mouths, the group reports in this week's Proceedings of the National Academy of Sciences USA.