Etemon

Digimon Adventure:

Etemon was the first major foe other than Nanomon the Chosen Children had to battle with after their arrival at the Server Continent. With the help of his Dark Network, it was able to monitor everything which happens in its territory.

In the end, it fused with the Dark Network and was defeated due to Greymon evolving to MetalGreymon. However, it was revived as MetalEtemon due to its own will power but was ultimately defeated by Zudomon's Hammer Boomerang and SaberLeomon.

Digimon Xros Wars:

Some Etemon serve Musyamon in the Shinobi Zone. They pretend to be Shoutmon's fans in order to find the Code Crown.