Alvin and the Chipmunks - Season 2 - Eps 16: Operation Theodore
While the Chipettes volunteer at the local hospital, a terrified tonsillectomy-bound kid goes missing, so until Brittany finds him, Theodore must step in to substitute, but the doctors, thinking he's the kid, take him into surgery.
About Alvin and the Chipmunks

Title: Alvin and the Chipmunks
First Air Date: 1983-09-17
Last Air Date: 1990-12-01
Status: Ended
Rating: 6.8/10 (from 74 votes)
Language: EN
Seasons: 9
Total Episodes: 172
Network: NBC
Genres: Animation, Comedy, Family
Production Companies: DiC Entertainment, Bagdasarian Productions, Ruby-Spears Productions, Murakami Wolf Swenson, A-1 Productions
Synopsis
Three chipmunk brothers, Alvin, Simon, and Theodore are adopted by human, Dave.
Cast

Ross Bagdasarian, Jr.
Alvin / Simon / Dave Seville (voice)

Janice Karman
Theodore / Brittany / Jeanette / Eleanor (voice)

Dody Goodman

Nancy Cartwright

Frank Welker

Tress MacNeille

Ross Bagdasarian