Thunderbirds - Season 1 - Eps 23: Attack of the Alligators!
When a new growth hormone is accidentally released into a South American river, a house is besieged by alligators – now many times their normal size. International Rescue must subdue the reptiles and save the house's occupants.
About Thunderbirds

Title: Thunderbirds
First Air Date: 1965-09-30
Last Air Date: 1966-12-25
Status: Ended
Rating: 7.6/10 (from 91 votes)
Language: EN
Seasons: 3
Total Episodes: 32
Network: Associated Television
Genres: Family, Action & Adventure, Animation, Sci-Fi & Fantasy
Production Companies: AP Films (APF), Century 21 Television, ITC Entertainment
Synopsis
Thunderbirds is a 1960s British science-fiction television series which was produced using a mixed method of marionette puppetry and scale-model special effects termed "Supermarionation". The series is set in the 21st century and follows the exploits of International Rescue, a secret organization formed to save people in mortal danger with the help of technologically advanced land, sea, air and space vehicles and equipment, launched from a hidden base on Tracy Island in the South Pacific Ocean.
Cast

Peter Dyneley
Jeff Tracy

Matt Zimmerman
Alan Tracy (voice)

Shane Rimmer
Scott Tracy

Ray Barrett
John Tracy

Sylvia Anderson
Lady Penelope Clayton Ward

David Holliday
Virgil Tracy (voice)

David Graham
Gordon Tracy / Brains (voice)

Christine Finn
Tin-Tin Kyrano (voice)