Primus

Primus is a planet introduced in the eponymous episode of Ben 10: Alien Force. Actually a giant organic machine created by Azmuth, it has been revealed to be the source of the DNA samples for the Prototype Omnitrix and Ultimatrix.

Backstory
Though not shown, Primus' existence was first hinted in Ghost Town when Vilgax freed Zs'Skayr in exchange for an unnamed secret about the Omnitrix. Zs'Skayr replied with a single word: "Primus." This secret is later revealed to be the existence and location of Primus in the eponymous episode, where the planet appeared.

Intending to disable the Omnitrix and take it from Ben, Vilgax went to Primus. Sensing his arrival, the planet called Azmuth and the Omnitrix. The Omnitrix was then taken from Ben to Azmuth to help him defeat Vilgax. The galactic conqueror eventually defeated him and took the Omnitrix, but was unable to use it. Upon learning how important Primus was for Azmuth, he threatened to destroy it, but Ben was able to trick him in order to take the Omnitrix from him and defeat him. After Vilgax was gone, Azmuth moved the location of Primus so Vilgax could not find it again.

Description
Primus appears as a jungle-like planet, full of vegetation and various unintelligent alien life forms, some of them dangerous. The main creatures on this planet are Voliticus Biopsis, mosquito/wasp-like robots created by Azmuth that travel the universe in order to find new alien DNA to add to the Codon Stream. The planet seems to have a mind of its own, as it was able to call Azmuth when Vilgax arrived.

The main element of Primus is the Codon Stream, a green liquid substance present throughout all the planet. It actually served as the database for the Omnitrix, containing all the DNA the Volicticus Biopsis found in the Milky Way Galaxy. The Omnitrix communicated with this database, which gave it the information necessary to modify Ben's genetic code and allow him to transform.

Connections

 * Omnitrix (Prototype) (formerly)
 * Albedo's Omnitrix (formerly)
 * Ultimatrix (formerly)
 * Unitrix (one way link)

Trivia

 * The Unitrix is not connected to Primus and has no need for this function as it was intended to store each alien DNA in its own separate container. As such, it does not have a wireless receiver like its later models, the Omnimatrix, Ultimatrix, and possibly the Omnitrix. Azmuth later added a one way connection to it so it could upload samples on its own. While active, this feature can cause interference with a nearby Omnitrix core that is connected..
 * It is mentioned in The Transmogrification of Eunice that Primus needs periodic care and maintenance which is proven true in Simian Says.
 * It is shown, without care and maintenance, that it can affect the operation of the Omnimatrix/Ultimatrix in the long run.
 * It is shown that Eunice is one of the planet's caretakers. It's possible Primus has other caretakers as well, since the planet is very big and Azmuth stated he could always use a helping hand tending Primus.
 * Primus' connection to the Prototype Omnitrix/Ultimatrix seems to have no problem at all in transcending dimensions. They are fully functional in the Null Void, Ledgerdomain, and even to places such as video games in Game Over, outside the universe like the hidden Forge of Creation and even in parallel universes as shown in Heroes United. This just proves how highly genius and technologically advanced the Galvans truly are.
 * Primus is a setting in Ben 10: Galactic Racing.
 * Before Azmuth invented the Prototype Omnitrix, Primus was a work in progress and did not have a DNA database.