Dolphmon

Dolphmon is a Sea Animal Digimon, born of special signals within the software used in conversation research. Due to this, Dolphmon's way of thinking is extremely complex and is better at learning than normal humans. It does not like fighting so it only battles if it has no choice. Its Japanese name is Rukamon, which comes from "iruka", the Japanese word for dolphin.

Digimon Adventure 02
A bunch of Dolphmon helped Ikkakumon, MegaSeadramon, Cody and Submarimon protect a Destiny Stone under the sea from BlackWarGreymon. However their attacks couldn't harm the powerful Mega Digimon. BlackWarGreymon then used an attack to part the sea, sending the Digimon flying away and unable to intervene.

Digimon Tamers
Something that might be Dolphmon was among the shadowed Digimon that wanted Rika to tame one of them. A silhouette of one appeared on Henry's computer.

Digimon Frontier
Despite being in the opening theme (1st ending credits in Japan), the DigiDestined never encounter one. In the Opening theme, three Dolphmon were seen with Takuya, Neemon and Bokomon on their backs.

Digimon Data Squad
10 Years Ago as told by SaberLeomon to the Gotsumon that worked for Merukimon, a Dolphmon was among the victims of the humans who were deleting Digimon.

Digimon World 2
Dolphmon digivolves from Penguinmon, and can digivolve further to Whamon.

Digimon World 3
Dolphmon appears as a random underwater enemy in Asuka server. He won't be found in the seabed that leads to Duel Island, which in both servers' case is populated by Divermon.

Digimon World Dawn/Dusk
Dolphmon digivolves from Betamon, and can digivolve to Whamon or Divermon. It can be found in Macro Sea.

Digimon Racing
Dolphmon are seen through the glass in the track Underwater.

Attacks
 * Pulse Blast (Shaking Pulse): Fires a powerful sound wave from its mouth.
 * Dolphin Kick: Hits the enemy with his tail fin.
 * Divine Rain: Attacks with a powerful waterball along with rain as it is executed or performed.