In the Resident Evil series, a number of alligators became infected with the T-virus during the Raccoon City Destruction Incident. Most of these specimens came from the Raccoon City Zoo, but there was one specimen that had been encountered in the city sewers by Leon Kennedy and Claire Redfield. It is unknown where this specimen came from originally, but its appearance in the sewers fulfills the old urban myth of alligators supposedly surviving in the sewers and growing to monstrous size.
Like with other reptilian creatures, the T-virus has caused the alligator to grow in size considerably. Its mouth is large enough to snap up a human whole. Leon and Claire fought against this mutant down in Raccoon City's sewers in a tunnel connecting the sewers to the water treatment plant. The alligator was so big that its body filled up most of the width of the tunnel, making it impossible to get past the creature. The pair were able to kill the alligator after knocking over a gas canister which the creature snapped up in its mouth. Shooting the canister caused it to explode, blasting the creature's head to pieces.
