The Frog is a large, carnivorous alien fish which lurks the blood oceans of Moon AT-5. It has caused the deaths of at least two humans.
Following the Quiet Rapture, the Consolidation of Iron roamed the universe for answers as to the reckoning of almost all known humans. When arriving upon AT-5, they observed that the moon was covered in blood. They had sent down a convict, who did not return alive due to The Frog, and sent yet another to the same fate.