D-Reaper

The D-Reaper is the true antagonist in Digimon Tamers. He is a very powerful digital lifeform that absorbs data from anything it touches, including the Real World (slower than in the Digital World, where it's far quicker). It can also absorb negative energy produced from humans. The D-Reaper was first fought in the Digital World by the Tamers, who actually managed to halt his actions for a short time. However, once the children returned to their world, the Reaper followed them and started to consume the whole area of Shinjuku, Tokyo, beggining by the Tokyo Metropolitan Government Building area (headquarters of Mitsuo Yamaki's Hypnos project). It can't be harmed directly, as only a few objects and people can enter it's bubble shield (called D-Reaper Zone) and see what's inside. The other reason is because the Reaper also holds Jeri Kato (Takato Matsuda's friend) as it's prisoner and energy source. The D-Reaper was voiced by Yoko Asada in the Japanese version and Bridget Hoffman in the english version in the same fashion as Jeri herself, only deeper and computer-altered.

Character
The D-Reaper is cold and calculist, not caring about human or digimon emotions or origins, as long as it provides development for it's total mass. Even though it keeps Jeri prisoner, it shows no concern for her depression or loneliness, just technical curiosity. The Reaper also shows a slight curiosity on human emotions and feelings, as it constantly tries to analyse Jeri's emotions on Takato and sorrow on Leomon's death.

Forms
The program has a huge variety of minions and forms born from the data it collects. It's agents (called ADRs, short for Agent of the D-Reaper) are mostly shaped Digimon-like, only connected to the "bubble" through a red cord that, if cut, weakens them greatly. The most important agents are the ADR-01: Jeri Type and ADR-09: Gatekeeper, both acting as the D-Reaper's main defense and offense. The most notable form is called the Mother D-Reaper, created from the data absorbed from Shinjuku's buildings and citizens, Digimons, and the ADRs 01 and 09. It evolved in a similar way to the Digimons (from the collected data) it consumed, however it didn't evolve into a creature, but to a superior form of it's own. The Mother form is a giant, tower-like structure made of many electrical and telephonical wires and cords, with buildings emerging from it's interior (they disappear later in the series). It also wears a big mask with six eyes and a crown-like ornament on it's head, the most noticeable detail being an orb in the middle of it's face (where Jeri is kept).