Gomamon looks like a white furry seal-like creature with no nose and has long ears, purple markings, orange-red mane, large claws, a short tail, and a W-shaped smile with two pointed teeth protruding out. He is the partner to Joe Kido.
Gomamon first appeared when he digivolved from Bukamon to protect Joe from Kuwagamon in episode one of Digimon Adventure. He is Joe's partner and his goal is to lighten Joe up, to make him less serious, using his own disarming and fun-loving character. Later in the adventure he digivolved to Ikkakumon when the Black-Gear-infected Unimon attacked the DigiDestined.
When the kids returned to the Real World to halt the plans of Myotismon on August 3, 1999, Joe and T.K. attempted to return to Odaiba. However, they were ambushed by MegaSeadramon while they were passing Rainbow Bridge. Joe, putting himself in danger to save T.K. from drowning, gave Ikkakumon the power to Digivolve to Zudomon, who defeated MegaSeadramon. Zudomon became a valued ally in the battles against Myotismon, MetalEtemon, the Dark Masters and Apocalymon. Before they went their separate ways, Joe thanked Gomamon for being a good friend.
Two years later, when the Digimon Emperor was conquering the Digital World, Gomamon was among the old generation Digimon to help the new gang out. One such event was when Gomamon challenged the Emperor when he was forcing some Gizamon to build a prison in the frozen north. He was attacked by the Gizamon, who were promised a reward by the Emperor if they did so. He was left for dead, but the second group of DigiDestined managed to save him and, they together destroyed the Control Spire.
He also came to the Real World on Christmas Eve and on Christmas day, helping to gather the Digimon who appeared world-wide along with Control Spires. He received a power boost from one of the DigiCores of Azulongmon, which restored his ability to Digivolve to Ultimate. The next day, however, during the battle with SkullSatamon of the Daemon Corps, the strain of being in the Real World got to Gomamon, so he and the others had to return. Gomamon was later seen during BlackWarGreymon's incursions into the real-world. He was later seen sealing the Hikarigaoka Gate and in the final battle against MaloMyotismon.
In Dimensions, he helps Joe defend their own reality from the Demon Lords in Book Three. Eventually, he gains the ability to Biomerge with Joe to reach his mega form, Vikemon in Book Four. While Joe is studying to become a doctor, Gomamon is trying not to die of boredom. He and the other older Digidestined and their partners live at the File Apartment.
- Marching Fishes: Gomamon gathers a hoard of fish friends to attack the enemy or to just help him out. Gomamon's attack was originally dubbed "Fish Power" in the early episodes of Digimon Adventure, but the attack was soon changed to the definitive "Marching Fishes".