Growlmon is Guilmon's champion form.
He looks similar to his Rookie form, but bigger.
Guilmon first digivolved to Growlmon while fighting Devidramon, and destroyed him. However, Takato couldn't figure out how to dedigivolve him, and he wouldn't fit in his cave, so he initially hid him in the cave where the digital zone once was. Impmon chased him out, shooting fireballs at him, until Growlmon fought back and fell asleep at the park where kids used his tail as a slide. Eventually Takato and Henry used paint to camouflage him in the forest, but the rain made the paint run off him. Then a rainbow appeared and Growlmon dedigivolved to Guilmon.
Guilmon digivolved to Growlmon again to fight Mihiramon, but was nearly killed until he matrix digivolved to WarGrowlmon and destroyed Mihiramon. However he did not need to digivolve past Growlmon to destroy Sandiramon and Sinduramon, although with the former he was powered up by a card Kazu gave Takato, and with the latter he knocked him into the water and electrocuted him.
Growlmon fought Vajramon, but was easily defeated.
He also fought Mephistomon and his minions, and had to digivolve to WarGrowlmon again to defeat him, although he nearly destroyed Mephistomon by shooting down a ship above him.
Somehow he digivolved to Growlmon without Takato, who had been separated from the others in the digital world.
- Dragon Slash - Activates a blade on his arm and slashes his enemy with it
- Pyro Blaster - Shoots a fireball at the enemy much bigger than Pyro Sphere