Gaiamon

Gaiamon is an Unknown level Digimon that would have been the fusion between Galacticmon and the planet Earth.

Digimon World 3
Gaiamon is Galacticmon's ultimate goal, and it would have been created by the merging of Galacticmon with planet Earth, resulting in the extinction of the human race and the creation of an unimaginably powerful entity. Because this event never occurs in the game, nobody knows what this enigma of a Digimon looks like or the true extent of its power.