Infermon

Infermon is an Unidentified Digimon whose name is derived from "Inferno" (Ita: "Hell") and whose design is derived from the Y2K Bug. It has the appearance of a long-legged spider, and while its form is usually in an outstretched state, with its head and limbs extended, it is also able to assume a cocoon form, with its limbs retracted into its body. When it goes into its cocoon form, its defensive power is raised such that every attack is deflected, but it can only go forward in a straight line, and the fact that it cannot modify its trajectory is a clear weakness. It is able to penetrate every Network, despite the strength of their security. If Infermon is released from the Network, the world will probably then collapse into chaos.

Digimon Adventure: Our War Game!
The Ultimate level Infermon form was reached through Warp Digivolution, thus bypassing the Adult/Champion stage, Chrysalimon. In this form, Greymon and Kabuterimon had a hard time fighting him. To defeat the powerful Digimon, they also planned to Digivolve on their Ultimate Level but while they were Digivolving, Infermon attacked them, resulting in their defeat. Infermon then escaped and hacked himself in the US military network, from where he launched a nuclear missile on the DigiDestined. Agumon and Gabumon attacked him in their Warp Digivolved forms, WarGreymon and MetalGarurumon. However, as the tides were against him, he Digivolved into Diaboromon, nearly killing both Patamon and Tentomon, the former in particular knocked out from being attacked in the midst of Digivolution to Angemon. This greatly enraged Tai and Matt, and they began to pummel him, that is, until Tai's computer froze, causing WarGreymon to do the same. Without the help of WarGreymon, MetalGarurumon was easily defeated by Diaboromon, who then escaped and began to clone himself.

Attacks
 * Spider Shooter (Cocoon Attack): His mouth opens to reveal a barrel-like cannon, shooting small flares.

Role in Ultima
In Ultima, Infermon.