Big Red

Big Red is a monster found in the sewers. He is said by some to be one of the scariest parts of the game, as he is encountered right after the sewers, which is infamous for it's settings and creatures. Madotsuki is eaten by him to proceed unto the next area.

Something notable is how he slightly resembles Dave Spector, a creature in Monochrome world that has similar eyes to Big Red.

Trivia
"Big Red" is a nickname for Satan.