|Jafar says: Read my lips and come to grips with the reality!|
|“||Even if me tired, you still get defeated good!||„|
Gigasmon is Grumblemon's Beast Spirit form an alter-ego.
Gigasmon is a beast-hybrid Digimon that resembles a rock-like giant with jagged edges on his arms and back and a big nose.
Gigasmon first appeared in episode 6 and easily defeated the heroes, separating them. In "You Can't Keep A Grumblemon Down", Gigasmon engaged Agunimon, Beetlemon, Kazemon, and Kumamon into a fight.
Just as Gigasmon was about to steal Tommy's Spirit, Kazemon pushed Kumamon out of the way and took the hit herself, and Zoe's Spirit was stolen. Gigasmon found Koji, who Spirit evolved into Lobomon, and easily knocked him to a wall, defeating him, but Gotsumon blocked his path so Koji can reclaim his Beast Spirit. Koji Beast-Spirited evolved into KendoGarurumon and fought Gigasmon, and was plunged into the water.
Grumblemon somehow survived the fall and once again Beast-Spirited evolved to Gigasmon while Agunimon, Beetlemon, and Kumamon fought his minion, Golemon. After Golemon was defeated by BurningGreymon, Gigasmon quickly retreated.
After Takuya gained control of his Beast Spirit, Gigasmon kidnapped Tommy and Takuya as Agunimon went in pursuit to get back Tommy, but failed. Takuya then Beast Spirited evolved to BurningGreymon and saved Tommy from the giant's grasp.
BurningGreymon slide-evolved to Agunimon and Gigasmon chased after Agunimon out of the woods. Agunimon tricked Gigasmon into using his Tectonic Slam attack, trapping himself with nowhere to escape (since there is no forest to burn down). Agunimon slide-evolved to BurningGreymon and defeated Gigasmon by burning him to a crisp by his Wildfire Tsunami attack, and took his Spirit, reverting back to Grumblemon.
- Quagmire Twister
- Tectonic Slam