A Yameba (ヤメーバ Yamēba ) (also known as X-clusters in Metroid Prime and Metroid Fusion: Prima's Official Strategy Guide) is an amoeba-like creature encountered in certain areas of Sector 1 in Metroid Fusion.
Yamebas share the ability to hover through the air, and has the ability to increase its size whenever an X Parasite merges with it. These creatures slowly drain off energy from Samus whenever she is in direct contact with their outer membranes, similar to a Metroid. However, Samus can effortlessly walk away from their grip to avoid damage, causing the Yameba to give chase in an attempt re-attach itself to her; these traits are shared with Mochtroids.
It somewhat resembles a Meboid, Bang or Flitt in appearance, which would seem to suggest that the Yameba is an infected and/or X-mimicked version of one of the mentioned creatures. It is possible however, that this organism was an entirely new creature which Samus has never encountered before that was among the captured specimens of the Biologic Space Laboratories.
In trailers for Fusion, their core nuclei are colored purple and their membranes are yellow, rather than the green core and blue membrane seen in the final version of the game. They are also seen on the Main Deck, where they never were in-game.
- Contrary to popular belief, this creature is not a Metroid. However, Metroid Prime and Metroid Fusion: Prima's Official Strategy Guide refers to them as Metroids in one instance.
- Metroid Fusion: The Official Nintendo Player's Guide refers to them as "blobs".