A Fiend-type duel monster from early days of the Yu-Gi-Oh! card game. Based on a Phyrexian card from Magic: the Gathering called Morinfen.
It gained its meme status in Japan as a "poster boy" for high-level, low-stat normal monster released in the early days of the game. This reputation can be likened to Shapesnatch's in the West and Leo Wizard's in China.