Big Jeffy also appeared as a member of Little Chrissy and the Alphabeats, in place of the Lavender Alphabeat, in the songs "I Go to School", "Startin' Kindergarten", and "Gonna Rock You to Sleep". He and Little Chrissy have also sung with Elmo on a few occasions.
He has also appeared without Little Jerry or Little Chrissy in the 1987 special A Muppet Family Christmas, as a background character.
Big Jeffy was named after Jeff Moss, who usually provided his voice. Though Jerry Nelson performed him in a sketch where the Monotones assist Grover in displaying the word "walk." He can also be heard as Jeffy in the songs "Telephone Rock" and "Danger."Jim Henson also performed Big Jeffy in another sketchdemonstrating scatting, and Kevin Clash performed him in a late 1980s episode where Little Jerry visits the street.
Beginning in the late 1980s, Big Jeffy began donning a leather jacket. During his gigs with Little Chrissy, it was replaced with a red Alphabeat shirt. In a 2000 episode during Little Jerry and the Monotones' comeback, it is revealed that he knows how to play piano.