Gaiamon

From Digimon - NeoWiki

Gaiamon was supposedly the final form of Vemmon, created by Galacticmon merging himself with the Earth. It was mentioned by Snatchmon in Digimon World 2003 and Digimon World 3 as he announced his plan to rule the galaxy. While its abilities were not known, Junior said that if the merge were successful, all life on Earth would be eliminated, and Snatchmon did not correct him. Instead of merging immediately after becoming Galacticmon, Snatchmon decided instead to spare Junior and challenge him in space to prove the abilities of his interim form. This proved to be his undoing as he was defeated before he reached Earth. As a result, Gaiamon's appearance is unknown.