He first appears in the Season 2 episode, Truck Commander, working at the junk yard. Willie and Si come to buy John Luke a truck, but don't have any luck, because all the trucks are junk. Here, Willie is quite annoyed by Squirrel's presence, and claims he is Si's evil twin. Frustrated, Willie leaves with John Luke, but Si seems quite interested in staying with Squirrel.
Squirrel makes a surprise return, in the Season 4 episode Hot Tub Grime Machine. The guys come to buy Godwin a hot tub. Frankly, Godwin finds a piece-of-crap hot tub, but loves it. Although it is quite old, and filled with infectious diseases, Godwin buys it from Squirrel.