Thog is a 9½-foot tall blue monster.[1] His size may make him imposing, but he has a sweet and gentle disposition.

He first appeared as one of Cosmo Scam's evil henchmen in the 1970 Christmas special The Great Santa Claus Switch, partnered with a green monster named Thig.

As a full-bodied Muppet, combined with his droopy, friendly face, Thog was especially well-suited to dance numbers, on television and in stage shows, and he was partnered with several famous ladies over the years. He appeared on stage with Nancy Sinatra as part of her stage show in 1971, and in the unfinished TV version Movin' with Nancy: Nice 'n' Easy (1973). Also in 1973, Thog was featured prominently in "Oh Babe What Would You Say," with Julie Andrews inThe Julie Andrews Hour. He also had a featured number in the 1974 pilot The Muppets Valentine Show, singing and dancing with "Real Live GirlMia Farrow.

On The Muppet Show, he could be seen in the opening theme (alongside Timmy MonsterSweetums, and two ofThe Mutations) from season two on. Thog appeared in a number of segments including: as a "dangerous" animal inepisode 110; reprising "Oh Babe What Would You Say," this time with Kaye Ballard, in episode 123; detonating a blast for "School's Out" in episode 307; and demolishing a desert research facility in Loretta Swit's number, "I Feel the Earth Move," in episode 502.

In 2003, Palisades Toys released a PVC mini figure of Thog, the first Thog toy ever produced.

As first revealed in behind-the-scenes photos[2] and trailers, Thog was present in The Muppets; his first appearance in a Muppet production for more than three decades. Here, Thog (rebuilt by Jim Kroupa) appears to be much larger than he was originally; in one scene, he briefly gets stuck going through the arches during the rehearsal for "The Muppet Show Theme" recreation, causing Thog to have to walk in front of them.