I was browsing the MP2D forums, and look what I stumbled apon.
“Ph Z 01: Phazon]
Phazon is the remaining energy from the physical metroid creature. After the metroid species was destroyed on Planet Zebes, the remaining space pirates experimented with fractal cloning. Fractal cloning is a process that enables the engineer to sample any know [sic] DNA and splice it with their own — -
end signal
* DATA SAVED 01”
This means what? Metroid produce phazon as a side effect.
This means nothing. It was (according to the topic) from the beta build, likely taken out because it, in ways, contradicts already set up parts of the Metroid universe.
See, Metroids undergo growth, like any other organism. The end stage (as far as its been revealed) is the Omega Metroid. However, nowhere in the lifespan does a Hunter Metroid appear. Phazon exposure in Metroids leads to mutation, the Hunter being a mutated Metroid. If Metroids produce Phazon, then how come they don’t mutate? But, they do...
They pop when killed.
Maybe they live forever if they always have something to eat. And maybe when they die they just vanish from existance. They are energy based.