ShadowGreymon is an Ultimate level Virus type digimon born from the determination to get revenge or to fight for an unjust cause. He takes the appearance of a Greymon who has turned gray. The flesh on his jaw, abdomen, and the tip of his tail has rotted away, revealing his bones. He has three black claws on each hand and foot, and also wears a dark gray skull helmet. His eyes are pitch black and he has thick black stripes on his tail, which are surrounded by thinner dark blue stripes. Black and gray flames flicker on both of his shoulders. ShadowGreymon has the ability to travel through shadows, allowing it to be the perfect nocturnal hunter. The Digital Hazard appears on his chest with a red coloration, but he doesn't have the power to destroy the entire Digital World like Megidramon does.
After Haku had digivolved to his Ultimate stage HelioHakumon for the first time and defeated his opponent, he reverted to his In-Training stage Hakitomon. At that moment, the viral clone of Haku that Volatilemon made decided to reveal himself. Brittani's digivice had allowed the clone (Darakumon) to digivolve to his Ultimate stage SetDarakumon due to the fact that the data that connected Haku to the digivice managed to survive the cloning process. SetDarakumon attacked Haku and reverted him to a Digi-Egg. At the time, Matthew was away from Brittani and when he heard her screams, he came running. SetDarakumon was already gone when Matthew and PrehistoricGreymon arrived. Brittani told them what happened, and Matthew became enraged. Brittani tried to calm him down, but he wouldn't listen. He knew PrehistoricGreymon would have difficulty facing an Ultimate level digimon, so he channeled his energy through his D-3 to him. PrehistoricGreymon dark digivolved into ShadowGreymon due to Matthew's determination for revenge. Matthew went with ShadowGreymon to hunt down SetDarakumon, but they couldn't find him. Matthew's anger went away, but ShadowGreymon's didn't. He destroyed smaller defenseless digimon who were in his path. When Matthew realized the monster he had created, he got away and followed his digimon until he ran out of energy. After a tearful conversation with AncientKoromon, the two of them returned to Brittani and promised they would control their anger better in the future.
ShadowGreymon appears again when Matthew and some of the villagers break into Volatilemon's laboratory to find out what he's up to. As Vaccine and Data type digimon would be out of place at the lab, the villagers decided that only Virus type digimon would be able to go. AncientTentomon told Matthew a legend about the Digi-Egg of Darkness that would turn a dark digivolved digimon into a controllable digimon. The Digi-Egg was found and Matthew was able to control his darkness and digivolved PrimitiveAgumon into ShadowGreymon to help out the few Virus type digimon from the village.
Darkness Flame- breathes black fire at the opponent
Shadow Burst- darkens the area around the opponent, travels through the shadows to behind the opponent, and rams the opponent with his horn