Red substance

This unnamed red substance, unofficially referenced as "acid", is a hazard that first appeared in the final Wily Castle stage in Mega Man 2. It appears as a large, red pool of liquid that drips from the ceiling. Many of these pools of liquid are seen all throughout the narrow passageways, and heavily damage Mega Man if he makes contact with either the drops or the ceiling pools, suggesting that it is corrosive, so the player must avoid these as much as possible.

In Mega Man: The Wily Wars, these pools of liquid appear in the final stage of the Wily Tower.

They appeared in the first DOS game in Dyna Man's stage, as well as the following stages in the DOS Mega Man 3:
 * Bit Man
 * Blade Man
 * Oil Man
 * Wave Man

Trivia

 * A similar hazard appears in Flame Mammoth's stage in Mega Man X, but it appears to be molten metal dripping from pipes.
 * Graviton releases a red "robot-destroying liquid" (ロボット破壊液) that is similar to this substance, but it is unknown if they are related.
 * Due to the drops being red in color, the acid drops seem to resemble blood.