Rugrats - Season 1 - Eps 23: Reptar's Revenge
The Rugrats hear that Reptar is supposed to be appearing in person at the Sleazola Bros. Fair, so they go looking for him there. But Reptar turns out to be more than just a mean green monster... He's a guy named Leo who loves to eat cereal.
About Rugrats

Title: Rugrats
First Air Date: 1991-08-11
Last Air Date: 2004-08-01
Status: Ended
Rating: 7.595/10 (from 702 votes)
Language: EN
Seasons: 10
Total Episodes: 322
Network: Nickelodeon
Genres: Family, Animation, Kids, Comedy
Production Companies: Klasky-Csupo, Nickelodeon Productions, Nickelodeon Animation Studio
Synopsis
Focuses on a group of toddlers, most prominently Tommy, Chuckie, Phil, Lil, and Angelica, and their day-to-day lives, usually involving common life experiences that become adventures in the babies' imaginations. Adults in the series are almost always unaware of what the children are up to; however, this only provides more room for the babies to explore and discover their surroundings.
Cast

E. G. Daily
Tommy Pickles (voice)

Kath Soucie
Phil DeVille / Lil DeVille (voice)

Cheryl Chase
Angelica Pickles (voice)

Dionne Quan
Kimi Finster (voice)

Tara Strong
Dil Pickles (voice)

Joe Alaskey
Grandpa Lou Pickles (voice)

Melanie Chartoff
Didi Pickles (voice)

Tress MacNeille
Charlotte Pickles (voice)

Jack Riley
Stu Pickles (voice)

Cree Summer
Susie Carmichael (voice)