Flat Dog is the main antagonist animal in Crocodile 2000. It is also appeared in the sequel Crocodile 2: Death Swamp.

Crocodile 2000

Upon reaching the shoreline, Claire found the crocodile's egg in her backpack and the group decided to fight back against the angry crocodilian. Sharpening sticks into spears, they waited for Flat Dog to come on land and regain her stolen egg. The wait wasn't long and before the crocodile even reached its egg, Brady charged forward and stuffed his spear into its maw. The teenager was forced back but not killed, and next up was Duncan. He also charged forward and tried to blind the monster by holding his sweatshirt over its eyes. Annoyed, Flat Dog merely threw her head back and swallowed Duncan whole, but thanks to all of the bug repellent on him, he was thrown up by the reptile and saved. As Brady revived Duncan, the egg began to hatch in Claire's hand and the baby reptile fell into its mother's tooth-filled maw. With her young back, Flat Dog turned around and the left the trio in peace and returned to the water…

Crocodile 2: Death Swamp

For the following year, she raised her surviving offspring and it steadily grew. However, when a plane crashed into her domain, her fifteen-foot child was shot and killed by the ruthless criminals that caused the crash. Enraged, the massive crocodile began to follow the few survivors of the crash. She began to pick them off one at a time, leaving a bloody trail of carnage through the swamplands. Mia’s boyfriend, having learned of the crash back in town, hired his own escort to help him locate his missing girlfriend within the swamps. Upon reuniting, the group was suddenly ambushed by the giant animal. 

The reptile killed two of the party and trapped the others in an abandoned structure in the middle of the wetlands. However, the shelter could only last for so long. The reptile managed to bring it down, sinking the flimsy structure and sending the struggling group fleeing. With the criminal ranks broken down and only one left, the survivors finally thought they reached safety upon arriving at the helicopter. However, the monstrous crocodile brought down the helicopter and began to chase Zach and Mia as they attempted to escape by raft. Unable to keep up with the speed gifted to the raft by its motor, the crocodile was lured into a section of the swamp filled with methane. Canisters of gasoline were poured into the dark water and ignited, setting off a chain reaction. The legendary beast was engulfed in several explosions, its body ripped apart and burned. At long last, the deadly reign of the man-eating reptile was ended.