- Frank Oz (Bert)
- Sonia Manzano (Maria Figueroa Rodriguez)
- Roscoe Orman (Gordon Robinson)
- Martin P. Robinson (Telly Monster/Aloysius Snuffleupagus/Irvine/Slimey (voice))
- Suki Lopez (Nina)
- Violet Tinnirello (Charlie)
- Jennifer Barnhart (Zoe (voice))
- Ryan Dillon (Elmo (voice))
- Alan Muraoka (Alan)
Sesame Street — S3E84
Episode: Bert leaves Ernie
Air Date: 1972-03-09
Overview
Ecology, and lessons on numbers and the alphabet are featured.