Massive tentacle

Unknown Life Form 25 can be found on the planet Phaaze, in the game Metroid Prime 3: Corruption. They are tentacles caused by Phazon corruption. The Scan Visor reveals them to be semi-sentient. They just shake in the background and sometimes shine with Phazon.

They can also be found on the Pirate Homeworld as Samus enters the planet and during the fight with Gandrayda. Strangely, when an enemy enters Hyper Mode, tentacle-like forms can be seen protruding out of their bodies, similar to the ones in Phaaze.