Gas

Gas, steam, and similars are hazards from the Mega Man games.

In Mega Man 5 and Mega Man for Game Gear it sprays in various intervals from the pipes in Wave Man's stage and deals damage when touched. To pass by the pipes safely, wait for the geyser to subside. Charge Kick can be used to get past them without taking damage. While not an enemy and immune to all attacks, it can be "destroyed" by transforming it into a 1UP with the Mystery Tank's effect. A similar hazard also appeared in Neptune's stage from Mega Man V.

In Mega Man X2, Flame Stag's stage contains pipes which spray a harmless gas that can be ignited by Morguns, temporarily changing it into a fiery spray.

In Mega Man ZX Advent, the Mysterious Lab contain pipes that continuously release gas. Grey must crouch or jump to pass them.