Culp was responsible for stealing Theramine from the laboratory, but he accidental knocked some of it down the sink and it was pumped into the swamp, mutating the alligators to enormous sizes.
Culp is a boatman on the Ambro river, who transports people in his river boat "Maria". He takes Blackmer up river to visit Dr. Orchard at his River House. When they arrive a violent storm breaks out and they must stay over night before travelling back to the river station
Culp the ThiefEdit
Culp over hears Dr. Orchard's talk on the use of Theramine and during the night sneaks into Mrs. Files room and steals the keys to the laboratory, after letting himself in, he takes the Theramine from the cupboard and pours some into a phial, in the process he accidentally tips some of the drug into the sink, washing it away into the river.
Big Trouble Down the PlugholeEdit
After Culp has replaced the Theramine with another liquid, he returns to the couch he has been allowed to sleep on for the night.
In the morning, when Culp ferries Blackmer back down the river, they are attacked by one of the alligators, that has overnight grown in enormous size. The Boat is overturned and the pair are thrown into the river. Blackmer is rescued by Hector McGill in a motor boat but there is no sign of Culp.
Back From The DeadEdit
Luckily for Culp he knows of the secret underground passageway built by the previous owner, and uses this to gain entrance to the house. Emerging from behind a bookcase he takes Scott by surprise and disarms him.
Culp's Final GetawayEdit
Culp intends to make a getaway with the phial of Theramine, threating to pour it into the swamp unless he is given clear passage. He sets off in Dr. Orchard's Motor Launch. Suddenly a fourth alligator attacks Culp's boat and he is thrown into the swamp, and is never to be seen again.