Earth-TUD3

Earth-TUD3 was one of the many universes in the original multiverse. The inhabitants of this universe almost destroyed Earth-19, which led to the creation of Earth-19's Collector Agency. It was presumably destroyed by antimatter during the Anti-Monitor Crisis.

Overview
This universe is a neighbor of Earth-19, presumably meaning that they are positioned next to each other.

History
At some point, the denizens of this universe came through a breach leading to Earth-19, invaded it, and almost destroyed the whole Earth. This prompted the inhabitants of Earth-19 to create the Collector Agency, an organization that prohibits entry and departure from the universe without the explicit permission of the agency. Violating their law was punishable by death.