The Darkness (also referred as the DArkn∊∬) is the main antagonist in Learning with Pibby.
It is a mass of darkness that can corrupt any cartoon character it assimilates into mindless, glitchy zombies, and it uses Bun Bun as the embodiment of darkness.
Where it is created and its motive is still currently unknown.
It will be killed by Pibby.
Chronicles of the Great New Empire
When Giygas destroyed worlds and devoured souls, the energy of the fallen worlds was left. For a very long time it accumulated until some semblance of life was born in it. And it went to absorb the worlds itself, destroying and subjugating all life. And so Darkness was born...