|This article belongs to the Classic Continuity|
The Plumber Headquarters is a location that appears in Alien Swarm and Omniverse. It is a functional Plumber Base, led by the Magister of Earth, Max Tennyson. One of the known entrances was through the Max's Plumbing shop bathroom before the base was moved into orbit above the Earth.
- It was first seen in Ben 10: Alien Swarm, when Ben went to Grandpa Max to ask about the Nanochips. At the time, it served primarily as a communications station.
- It re-appeared in The More Things Change: Part 1, when Ben visited Max.
- In Trouble Helix, Ben was training there with Blukic and Driba. Khyber infiltrated the base to get information about Ben and Malware.
- In Outbreak, It was invaded by Dr. Psychobos and his robots. After the Omnitrix malfunctioned, some prisoners were transformed into some of Ben's aliens. The prisoners tried to escape from the prison, but were defeated by Ben, Rook and their team and were sent back to their cells.
- In The Final Countdown, the HQ was launched into the orbit after Kundo tried to self-destruct it using his newfound cybernetic powers.
- Aloysius Animo
- Dr. Psychobos
- Acid Breath
- Nyancy Chan
- Violet Offenders
- Michael Morningstar
- Solid Plugg
- Charles Zenith
- V.V. Argost
- Ben 10: Alien Swarm (first appearance)
- Season 1
- The More Things Change: Part 1 (first re-appearance)
- The More Things Change: Part 2
- A Jolt from the Past
- It Was Them
- So Long, and Thanks for All the Smoothies
- Trouble Helix
- Have I Got a Deal for You
- Of Predators and Prey: Part 1
- Season 2
- Season 3
- Season 4
- Season 5
- Season 6
- Season 7
- Season 8