Parasimon is a Parasite Digimon whose name and design are derived from "Parasite". It is a special Digimon that can't survive without leeching off of other beings, even though it is a Mega. Parasimon is powerless when by itself, but when it gathers in numbers, it can easily defeat Champion Digimon. When Parasimon leeches off of another, it can draw out the host Digimon's abilities to their utmost limit, exhibiting a terrifying power. Also, it can amplify the host's desires, and it is capable of taking advantage of those weaknesses. The existence of Parasite Digimon types other than Parasimon has been confirmed, and the influence of Parasite Digimon, in addition to viralization, is considered the cause of berserk Digimon.