- Attack of the 50-Foot Whatever: The Alligators.
- Big Damn Villains: Culp's escape gets foiled by giant alligator.
- Dramatic Thunder: A convenient storm means the scientists all have to spend the night in the remote house...
- Excited Show Title!: In keeping with this episode's 50's horror feel.
- Hoist by His Own Petard - Culp, the bad guy who released the growth hormone into the swamp, gets eaten by a giant gator himself.
- Leeroy Jenkins: Alan, who rushes in to lure the last alligator away from the house. It works, but he nearly gets killed.
- No Animals Were Harmed - Unfortunately not the case, despite the production team's best efforts. Some members of the production team refused to cooperate, and there was a representative from the RSPCA on set to ensure a minimalization of animal abuse. The production team used electric shocks to get the "gators" (actually juvenile crocodiles) to go where they wanted, and the crew recalled that when the RSPCA man found out, he pointed out that the crocs wouldn't even feel the 20V they were using, and recommended upping it to 60V! Still, some of the young crocs sustained minor injuries, and one unfortunately died of hypothermia overnight. They were also rather aggressive with handlers and one of them ate the legs off a Lady Penelope puppet.
- Obviously Evil: Culp
- Old Retainer: Mrs. Files, who serves as a bit of a Red Herring in the beginning as she looks like she might be a bad guy. She isn't.
- Ridiculously Cute Critter: The pygmy alligator that Alan gets for his birthday.
- Reluctant Mad Scientist: Orchard, who would rather not see his growth formula fall into the wrong hands. Better pay attention to that unsavory boatman you've got lurking around the lab...
- Secret Underground Passage: Mrs. Files mentions the previous owner of the house, Lopez, had one of these installed, but never told her it's location. This looks like it's going to be vital to the rescue, but the passage only end up saving Culp's life (at first), who knew about the tunnel since he was a close associate of Lopez.
- Slurpasaur: Little crocodiles play giant alligators.
- Special Effects Failure: The tradition peril of scale models, particularly in watery environments - it's very obvious that the "giant" alligators are small crocs in a tank.
Recap / Thunderbirds S 1 E 23 Attack Of The Alligators
The One with... the alligators.An experimental growth hormone is accidentally released into the South American jungle. This causes the local alligator population to grow to ten times normal size. A house in the jungle is besieged by the vast monsters, and it falls to International Rescue to save the people within!