Forced to make an emergency landing during a storm, the Pussy Cats land on an island. They are captured by Dr. Madro, who has been performing strange experiments. Madro turns Alexander into a gorilla, But Alex cares more about rescuing his friends and sister than becoming human again.
- The episode is loosely based on science-fiction classics, including Mysterious Island by Jules Verne, The Island of Dr. Moreau by H.G. Wells, and Planet of the Apes by Pierre Boulle.
- Sherry Alberoni as Alexandra Cabot
- Barbara Pariot as Valerie Brown
- Jerry Dexter as Alan Mayberry
- Jackie Joseph as Melody Valentine
- Casey Kasem as Alexander Cabot III, Pet Shop Owner
- Don Messick as Sebastian
- Janet Waldo as Josie McCoy, Villager
- Hal Smith as Dr. Madro
- John Stephenson as Pilot
- Barney Phillips as Croog