This immobile sentry is mounted on walls in the ruins of SR388, and becomes active only when an unrecognized lifeform enters range. The Wallfire is capable of projecting fireballs towards any threats, which can be frozen with the Ice Beam. They are also capable of regenerating damage if no threats are nearby. Wallfires reappear in Metroid: Samus Returns, and although they are immobile, they can aim more precisely at enemies. Instead of launching fireballs, most now produce flames like those of a flamethrower (there are however fast fireball shooting variants, that can be slowed down using Phase Drift). Indestructible variants are found in Area 2 in Samus Returns (these can be destroyed with the second Aeion ability which causes them to overheat and explode), as well as destructible ones.

The Golden Torizo occasionally throws spheres that hatch into flying bird heads that resemble Wallfires.