Super Metroid
Powamps float immobile in the water of Maridia, inflating when Samus Aran approaches. Despite their docile nature, they can still damage Samus upon contact with Samus, and will explode if shot, sending out many projectiles.They can be latched onto using the Grapple Beam to be used as a Grapple Point.
 Metroid Fusion
In Metroid Fusion, there are several X-parasite infected Powamps and mimics aboard the B.S.L.. They have been modified by the X to have a darker shade of colouring, and now have a spiky exterior. They are encountered only in Sector 4, a watery environment not unlike Maridia. They can be frozen by the Ice Missile.
In some situations, it isn't possible to hit a Powamp directly with an Ice Missile. However, they can still be frozen if the Ice Missile is charged up to unleash a Diffusion Missile, which will freeze enemies in its blast radius.