A black hole is an astronomical feature that occurs when a massive star collapses into an extremely small singularity so dense than not even light can escape its gravitational field.
Sometime after he departed Cybertron, the T-Cog of Amalgamous Prime wound up near a black hole. It remained there until it was found by a group of refugees fleeing Neutronia who brought it aboard their ship lest the black hole destroy the legendary artifact.
The Requiem Blaster works by drawing power from the gravity of a black hole, a quasar's sound waves, or a supernova's thermal energy (whichever is closer).
The Solaris particle collider was believed to be able to generate power sufficient to create a black hole. It was this information that led Ratchet to deduce that the end goal of the Decepticons' raids was to rebuild the Omega Lock.
After being stranded on Earth, Thunderhoof attempted to construct a Space Bridge to return home. The sub-standard human materials used in its construction however caused the portal to collapse into a black hole.