Fission Metroids are Tallon Metroids mutated by exposure to pure Phazon. When one of these creatures is struck by any weapon, they will split into two Metroids. The split creatures will be one of four colours: yellow, purple, red and blue. The different colours indicate what weapon that Metroid is vulnerable to. Yellow: Power Beam. Purple: Wave Beam. Red: Plasma Beam. Blue: Ice Beam. Like with other Metroids, Samus can use Morph Ball Bombs to dislodge a Metroid that latches on to her. Power Bombs are also very useful when surrounded by multiple Fission Metroids since they can kill any colour Fission instantly and have a wide blast radius.