Tau Volantis Moon

The Tau Volantis Moon is a largo moon sized Necromorph and member of the Brother Moons network. This massive creature is responsible for the destruction and consumption of almost all life on the planet Tau Volantis, until the inhabitants of the planet were able to create a massive machine to freeze the creature, effectively putting it into hibernation. The Tau Volantis Moon is the final antagonist in Dead Space 3

Dead Space 3
The Moon is a massive Necromorph and one of the Brethren Moons that serve as the origin of the Markers' signals. It is the result of an incomplete Convergance event: the last stage of the Necromorphs evolution. The Moon serves as the final boss of Dead Space 3. This is easily the single most powerful necromorph in the series thus far, incomplete as it is.

After Jacob Danik  deactivated the alien machine on Tau Volantis , the Moon was able to begin completing the Convergance Event  it began long ago. When Isaac Clarke  reactivated and completed the machine, the Moon collided with the surface of the planet and was destroyed.