UltimateBrachiomon is a giant brachiosaurus-like Digimon used by the DigiDestined.
Alex & Taylor encounter UltimateBrachiomon when he is guarding the Thunder Slingers they need to fight the SuperClaymon. He attacks them, forcing the two outsmart him to claim the weapons. Taylor later believes he is a villain, but Seraphimon calls him a powerful ally & friend. When the DigiDestined have trouble with defeating one of Lilithmon's Digimon, they call UltimateBrachiomon & CoreOmnimon will dock onto his back.
UltimateBrachiomon by himself is armed with several cannons. He usually will fire blasts out of his mouth, such as his first encounter with Taylor & Alex, but can move his tail into two shoulder cannons as well. The shoulder cannons are most prominently featured as part of "CoreOmnimon + UltimateBrachiomon".
When the DigiDestined get their Thunder Digimon, UltimateBrachiomon moves to the background to give place to Ebonwumon in Season 2. In Season 3, UltimateBrachiomon returns & is modified by Kokuwamon to combine with the DigiDestined's new Digimon.
UltimateBrachiomon is lost in time when Barbamon alters time on Earth with the Orb of Doom.