ShogunGekomon is an Amphibian Digimon. His name originates from the words shogun, a high-ranking noble in Feudal Japan, and gekogeko, the Japanese word for the sound that a frog makes (gerogero). He is known as TonosamaGekomon in Japan, which is a pun on a title of a feudal lord (Tonosama) and bullfrog (tonosamakaeru). His nickname is the "Sleeping Tyrant". The two horns on his shoulders and topknot on his head symbolize his dignity, so if either were tampered with, he would consider it an insult. He originally was born from a computerized scoring system used in karaoke. His singing voice can be manipulated scale-wise by his two horns, which also act as brass instruments. His voice is far lower than a Gekomon's, making him the samurai lord of all Gekomon. There are two tape strips across his belly, where it indicates ShogunGekomon has an outie navel (belly button). He also has two claw-like whiskers. ShogunGekomon takes the form of a toad/bullfrog, and still retains a crazed look. ShogunGekomon notably has much more strength and muscles than the spindly Gekomon, and you can see its veins bulging out. He rules over all the Gekomon and Otamamon in a swamp.
The first ShogunGekomon seen was in a castle where his Otamamon and Gekomon servants worked, here being called simply "Shogunmon" by his subjects. A long time ago he lost a Karaoke contest and thus fell into a deep sleep out of sorrow. The Gekomon and Otamamon were told by DemiDevimon that Mimi was the one to wake their master by singing. Tai, Joe, Agumon and Gomamon also tried to sing, but they failed because of their "wonderful" voices. Mimi then was convinced to sing completely because of the lesson she learned valuing the importance of friendship over wealth. When that finally happened, he woke up grumpy and started to attack everyone and everything. Palmon digivolved to Togemon to save Mimi from being flattened from the falling ceiling and MetalGreymon used his Giga Blaster attack to knock ShogunGekomon unconscious again. Later, when the Dark Masters attacked, a bunch of Gekomon and Otamamon from the castle assisted the DigiDestined's in the final battle against Piedmon and Vilemon. It is implied by the Gekomon and Otamamon that ShogunGekomon had been killed by the Dark Masters.
Three years later (in Digimon Adventure 02) in the Night Forest, a small group of same Gekomon and Otamamon that were friends with Mimi ended up under the control of the Digimon Emperor's Dark Rings and were freed when Togemon and Halsemon took down the Roachmon Brothers and the Control Spire. Later, in a village under the control of the Dark Rings, the members of ShogunGekomon's group were found hiding underground and offered hospitality to the DigiDestined. A Ninjamon slipped a Dark Spiral on ShogunGekomon while he and the DigiDestined were sleeping (as his solution to the Digimon Emperor taking over his territory was going to sleep and his love of sleeping was a running gag at this point), he went on a rampage. Pegasusmon and Nefertimon tricked him into attacking the Control Spire and he was knocked unconscious by Raidramon and Digmon. Raidramon, Shurimon, Digmon, Pegasusmon, and Nefertimon destroyed the Dark Spiral.
The most prominent Gekomon that appears in these seasons has a lisp that slurs his words and lengthens the S of his words. He appears to be the unofficial leader of the other Gekomon and Otamamon.