Negamon

Negamon (ネガーモン)
A Baby Digimon that grew up immersed in the negative data that the Network is overflowing with. It lives quietly in jet-black darkness, constantly awaiting its death. It appears before approaching Digimon, and makes them prey on themselves with the curse of its "Downer Eye". It is said that the Digimon that have preyed on themselves gradually lose their emotions, fall into darkness, and corrode from the inside out, becoming a seedbed for Negamon to regenerate.

Etymology
Nega: From negative.

TCG
There are currently no cards featuring Negamon in any Digimon TCG.