In the inaugural series, produced for the 1973/74 season, the five core heroes are joined by Wendy Harris and Marvin White (the "Junior Super Friends") and Marvin's pet, Wonder Dog. The heroes assemble in the Hall of Justice and receive assignments from Colonel Wilcox. Each of the 16 episodes was an hour long, and the "villains" tended to be well-intentioned extremists. When Super Friends was revived in 1977, the stories were reduced to fit the standard 30-minute slot. Wendy, Marvin and Wonder Dog were replaced by Zan and Jayna, the shape-shifting Wonder Twins, and their pet monkey, Gleek.