Undertown

Undertown is a subterranean alien city on Earth. It is one of the major settings for Ben 10: Omniverse.

History
Undertown is an underground alien city where many kinds of alien species live and thrive there below Bellwood.

In The More Things Change: Part 2, Ben Tennyson firsts discovers this when Ben and Rook Blonko pursue Psyphon's minions Bubble Helmet, Fistina, and Liam. Ben discovered that Psyphon had been using Undertown as a base of his racketeering operation. Ben ended up fighting Psyphon, Bubble Helmet, Fistina, Liam, Thunderpig, and other unnamed henchmen of Psyphon while fighting Khyber's Dog in the form of Slamworm at the same time. After Ben fought off Slamworm, Psyphon and his followers were arrested.

In Hot Stretch, Ben and Rook follow Ester to a deeper section in Undertown where the Kraaho made plans to make Earth hotter for them to survive in.

Known locations

 * Blarney T. Hokestar's Wagon
 * Lair of the Kraaho
 * Pakmar's Pet Store
 * Blarney T. Hokestar's store
 * Alien Salon
 * Y-it's Scooter Rentals
 * Pakmar's Fine Teas

Notable Inhabitants

 * Pakmar
 * Blarney T. Hokestar
 * Kraaho
 * Ester
 * Seebik
 * Lackno
 * Rabbit like alien
 * Derrick J. Wyatt

Ben 10 Omniverse

 * The More Things Change: Part 1 (first appearance)
 * The More Things Change: Part 2
 * Have I Got a Deal for You
 * Hot Stretch
 * Of Predators and Prey: Part 1
 * Of Predators and Prey: Part 2
 * Many Happy Returns
 * Gone Fishin'

Trivia

 * According to Derrick J Wyatt, Undertown has been underneath Bellwood since sometime fairly after Destroy All Aliens.
 * As of A Jolt from the Past, Undertown is, at least partly, powered by a volunteer group of Megawhatts who were freed from imprisonment by Ben and Rook.