The Fune is a large stationary creature found on Zebes. It is a strange creature that lives in the walls of hot caverns; all that is visible of it are its head and its mouth. A Fune can launch blue-hot fireballs from its mouth when it feels threatened. The only way to kill this creature is with a direct shot from a Super Missile. Except for the lack of any visible optical organ(s), they share a great resemblance with Namihes; Metroid Fusion suggests that Namihes are matured Funes.
Samus encounters X Parasite-infected Funes and/or X mimicking the creatures in Sector 3 of the Biologic Space Laboratories research station. The X-mimic version appears to have sacrificed durability (they can be damaged by charged shots and regular Missiles) in exchange for an extendable neck which they can use to lunge out of the wall when Samus approaches. Once extended, Fune-X can be frozen with Ice Missiles to make handy platforms. Fune-X can still spit out fireball-like projectiles that fly directly in front of the creatures.
As mentioned earlier, Metroid Fusion suggests that Namihes are possibly mature Funes, as almost all Fune-X change into Namihe-X at a certain point in the game. Since the X Parasites often seem to imitate the natural behavior of their infected victims, they could have followed the natural evolutionary path from Fune to Namihe.
As previously mentioned, the Funes seen in the BSL Station and in the BOTTLE SHIP can extend their bodies and exit their nesting holes (revealing themselves to be worm-like beings) respectively, contrary to the original variant which was a seemingly passive predator back on Zebes. It is possible that Galactic Federation researchers modified the physiology and/or behavior of natural Funes to turn them into efficient bioweapons.
"They spew forth red-hot fireballs from their mouths."
- The Fune as well as the Nahime, with their lunging attack, may be a reference to the inner jaw of the Alien in the Alien film franchise (Xenomorph), which greatly inspired Metroid.
- The Super Metroid Nintendo Player's Guide clearly states that Fune fires "red-hot fireballs", but in actuality the fireballs are blue.
- Metroid Fusion: The Official Nintendo Player's Guide refers to Funes as "long-necked creatures".