|The following is based on Fallout Tactics 2 and has not been confirmed by canon sources.|
Bipedal, mutated crocodiles or alligators can be found in Florida. Nothing is known about them except for a few concept arts by Tariq Raheem. In one of them, the creature is apparently wearing clothing, indicating at least some of them being a sapient race.
The mutant crocodiles were to appear in the canceled Fallout Tactics 2.