Watch as Elmo and Abby pitch in to help Mr. Earth (actor Paul Rudd in a hilariously large costume) host Sesame Street's first Earth-a-Thon. Mr. Earth teaches Elmo and Abby how "it can be easy being green" by recycling, re-using, and conserving water and energy. Abby, in her desire to help Elmo be more "green," accidentally turns him the color green and can't remember how to change him back! Lots of fun ensues as Abby is eventually able to poof Elmo red again. Elmo, Cookie Monster, Rosita and Telly join Mr. Earth in pledging to continue to do "green" things to help our planet because Earth Rocks!