This special aired in place of The Ed Sullivan Show (1948). Ed Sullivan gave Jim Henson and his company the timeslot as a Christmas present in gratitude for the many appearances the Muppets made on his show.
This special featured the first appearance of Gonzo, though he is named "Snarl" here.
This marks the first appearance of the Muppet Thog, who would later be retooled in 'The Muppet Show' as a kinder, gentler character.