Dorumon

Dorumon is a Beast Digimon whose name is derived from " D IGITAL OR U NKNOWN MON STER". Because of the old-style interface on its forehead, it is thought that Dorumon is an experimental prototype Digimon from before Digimon were discovered. Initially this Digimon's battle-personality had manifested too strongly, but it seems that it was eventually tamed by someone it had bitten. In an experiment, it was discovered that hidden deep within its DigiCore is the data of a legendary dragon, and it is thought that this gives it the ability to grow into a mighty Digimon. It naturally carries the X-Antibody, causing it to be ostracized by its peers, but its existence will turn out to affect the fate of the Digital World itself.

Digimon Chronicle
Dorumon is Kouta Doumoto's partner. He soon digivolves into Dorugamon in 1.0, but is a Reptiledramon in 3.0.

Digimon World 4
Dorumon is a Bash specialist, and is one of the four starting Digimon.

Digimon World Data Squad
Its a digivolution of Agumon and you can get it if Agumon digivolve into 6 DR type digimons,later you digivolve them into Belphemon.

Digimon World DS
Dorumon digivolves from Dorimon, and can digivolve further into Dorugamon with high level and high Beast EXP. Dorumon also prevents you from entering the Back Equipment and Back Item Shops if you are not a Silver Tamer.

Digimon World Dawn and Dusk
Dorumon digivolves from Dorimon and can further digivolve into Dorugamon with 800 beast exp, attack 125, level 24 or Drimogemon with attack 90, level 19, and minimum aptitude of 25.

Attacks
 * Metal Cannon: Shoots one or more metal balls from its mouth.
 * Dash Metal
 * Hyper Dash Metal
 * Dino Tooth

Digimon Battle
Dorumon is an event starter, and digivolves to DexDorugamon at lvl 21, DexDorugreymon at lvl 31 and DexDorugoramon at lvl 41.

There was also a "Mutant Dorimon" event, which a NPC gives a Dorimon (Dorumon's In-Training form) with unusual digivolutions, such as Guardromon as a champion form instead of Dorugamon or DexDorugamon, and Raijinmon as its mega form instead of DexDorugoramon or Alphamon.