Intelligent middle son who theorizes about the island's geography; accompanies his brothers on expeditions, competes for Roberta's affection, and ultimately leaves for university in London.
The Toymaker's brilliant but clumsy apprentice who invents a shrinking gun. He accidentally causes a factory explosion, warns about the weapon's dangers, gets shrunk by Barnaby, and ultimately helps reverse the shrinking spell to restore the heroes.
Alonzo's son and Medfield's star basketball player, initially ineligible due to failing grades.
A student studying in Florence who finds romance with Annette. Together they uncover an elaborate art forgery ring, confront the mastermind, and are thrown into an ancient dungeon.
Martian intelligence officer sent to scout Earth but falls for a local girl.
Midvale College student and protagonist who invents a mind-reading helmet and later uses hypnotism. His experiments lead to legal trouble, a break-in at the judge's house, and his temporary imprisonment, while ultimately exposing the judge's hidden criminal nature.
Dop is the leader of the five-man Martian mission sent to Earth to obtain women and save Mars from its genetic inability to produce female children. Disguised as an Earth man, he helps pursue and abduct candidates, but falls in love with Dr. Bolen and prepares to undermine the mission before returning to Mars.
Mike is Nancy's boyfriend and one of the principal adults resisting the teenage giants. He helps organize the counterattack, asks Genius to create ether, works with Horsey to rescue Nancy and the sheriff's daughter, and distracts Fred long enough for the hostages to be freed before knocking Fred out.
Wayne Thomas is a friendly paleontologist who encounters the stranded newlyweds and helps investigate their disabled car. After Greely attacks him, Wayne survives a severe wound and remains resourceful in captivity, hiding dynamite and resisting Greely's threats. He ultimately overpowers Greely and escapes with Leilla.
Teenage son left in charge of family farm, bonds with dog Old Yeller, faces Apache threats.
A teenager arriving on Catalina Island who investigates the theft of an ancient Chinese scroll with his friends and secretly returns it to the museum after confronting the antagonists.
Tommy Kirk has 44 screen credits in a career dating back to 1954. Their work spans 4 cinematic universes — most prominently The Old Yeller Collection with 2 titles. Signature works include Old Yeller, It's Alive, Mars Needs Women. Explore the interactive character relationship maps on each title page to trace how their roles connect across franchises.
Universe traveler — spans 4 universes
Related entry on Wikidata (Q2441024), public domain (CC0).
