Anunnaki (Scooby-Doo! Mystery Incorporated)

The Annunaki are a race of creatures living in another dimension. Every few thousand years, during an event called Nibiru, the barrier between their world and ours grow weak, allowing the Annunaki to visit Earth.

Some of them are good and tend to help humans, while others are evil. It was revealed that the sarcophagus buried beneath Crystal Cove contains the most evil of Annunaki.

The Annunaki have no physical forms, so they have to inhabit various animals' bodies. It is revealed that the animals which can talk are descendants of the Annunaki. Scooby Doo is one of them.