The Flintstones - Season 6 - Eps 16: Fred Goes Ape
A mix-up at the pharmacy gives Fred pills that turn him into an ape. Barney is the only one to see this short-lived effect, which makes him wonder about his own health. But when the two dads take their kids to the zoo and Fred ends up in the monkey cage after taking another pill, his problem becomes apparent to all.
About The Flintstones

Title: The Flintstones
First Air Date: 1960-09-30
Last Air Date: 1966-04-01
Status: Ended
Rating: 7.427/10 (from 924 votes)
Language: EN
Seasons: 7
Total Episodes: 166
Network: ABC
Genres: Family, Animation, Comedy, Kids
Production Companies: Hanna-Barbera Productions, Screen Gems Television
Synopsis
The misadventures of two modern-day Stone Age families, the Flintstones and the Rubbles.
Cast

Alan Reed
Fred Flintstone (voice)

Mel Blanc
Barney Rubble (voice)

Jean Vander Pyl
Wilma Flintstone (voice)

Gerry Johnson
Betty Rubble (voice)

Don Messick
Bamm-Bamm Rubble (voice)