During the Clone Wars, in a Wild Space star system named Chrelythiumn, a massive octahedron monolith appeared as a gateway to the planet of Mortis. On the outside, the octahedron was 5 kilometers long, both deep and wide, and was etched with red lines and a black surface.
When the monolith revealed itself by sending out a 2,000 year-old distress signal, only the Chosen One, Anakin Skywalker, and his Jedi companions were able to see the monolith from their shuttle, as the Republic forces Skywalker was supposed to rendezvous with were oblivious to its sudden appearance. This was due to the fact that the Father, a powerful Force wielder living on Mortis as an anchorite, sought an audience with Skywalker to test if he truly was the Chosen One and had lured him there.
Once Skywalker and the shuttle, along with the Padawan Ahsoka Tano and Jedi Master Obi-Wan Kenobi, noticed the appearance of the monolith, its gravitational force pulled the trio into its gateway, bathing them in a blinding white light. When the trio came to some time after, they awoke on the terrestrial realm of Mortis. The monolith disappeared after Skywalker and his companions eventually escaped Mortis, with no evidence of its appearance left behind in the star system.
- Star Wars: The Clone Wars – "Overlords" (First appearance)
- Star Wars: The Clone Wars – "Altar of Mortis" (Appears in flashback(s))