Chimerian Hammer (Classic)

The Chimerian Hammer is Vilgax's space ship during the original series, the first one was destroyed when Vilgax was strapped to a warhead by Max Tennyson. Vilgax stayed on the second ship while he was healing. It was destroyed when Max gave the self-destruct sequence to the ship. In the Alien Force episode The Secret of Chromastone, it appeared in a flashback.

Backstory
It is seen in the very first episode of the original series, going after Xylene's ship as it was carrying the Omnitrix. Both ships were damaged in the battle, with Xylene's ship being completely destroyed (save for the bridge which crash-landed on Earth) and a devastating strike hitting the Chimerian Hammers' bridge, crippling the Murrayan captain in the process as they crossed through the Sol System above Earth.

This prompted Xylene to send the Omnitrix in an escape pod set on course for the planet in hopes of reaching Max Tennyson. During the first season of Ben 10, the Chimerian Hammer stayed in orbit above Earth while Vilgax slowly recuperated from his otherwise near-fatal injuries, sending his Hover Drones down to Earth every now and again in order to search for the Omnitrix.

After being augmented with cybernetic/biological enhancements, Vilgax decided to go and claim his prize for himself. Landing his vessel near the grasslands of South Dakota, Vilgax and his entire army of drones set out to attack Rapid City in order to draw out the wielder of the Omnitrix so he could capture him.

After a brief fight against Ben Tennyson, Vilgax managed to capture him and bring him aboard the Chimerian Hammer in order to cut off Ben's hand and get the Omnitrix, planning to destroy the Earth once they've reached space, only for Max Tennyson to arrive in the Rust Bucket to save his grandson.

After overloading the engine core, the Chimerian Hammer was destroyed in a massive explosion, seeming to kill the Chimera Sui Generis and ending his threat to the Earth for good. It was revealed in the following episode that the Chimerian Hammer was not Vilgax's first ship, having already possessed a similarly designed vessel beforehand when he was younger.

He was stealing nuclear warheads from a military base for his own purposes only for the Plumbers to step in and stop him; fastening him to one of the nuclear warheads and firing it at his flagship, destroying it. this incident had Max along with the majority of Earth's Plumbers forces believed that the Chimera Sui Generis died in the explosion.

In season 3 of Ben 10 Alien Force, Vilgax returns with yet another Chimerian Hammer, only it's not referred by name. The Chimerian Hammer Mk. 3 is completely different from its two predecessors, it is more sterile and metallic-looking than the otherwise biologically oriented Mk. 1 and 2 both were.

Vilgax, having absorbed the powers of 10 heroes; seemingly no longer needs the Chimerian Hammer in order to traverse space, having the ability to fly and survive in the vacuum for prolonged periods of time, he must require it in order to transport his Energy Transfer Device, along with his Drone soldiers and later his Bioids.

Vilgax used the Mk. 3 on several occasions throughout the season (although not as much as the Mk. 2 was), having been used by Vilgax in order to reach Primus (most likely was going to use its weapons systems to destroy the planet just as he planned to do to Earth 5 years ago), and then later appearing in the Final Battle, where he used it to transport his Bioid Army, and after claiming the Omnitrix, was going to use them to conquer even more worlds after destroying the Earth out of his anger for being defeated by it continuously.

When Ben activated the Omnitrix self-destruct, Vilgax was left without his shape-shifting army, and damaged the Chimerian Hammer Mk. 3s guidance system in order to crash into Bellwood; destroying it and everything else for 100-miles around: killing thousands as a result. While Ben and Kevin fought against Vilgax, Gwen and Max made it to the control room in order to steer the ship into the Pacific Ocean and ditch it where it wouldn't harm anyone.

As the flagship crashed into the ocean, it automatically began to pressurize as the denseness of the ocean began to slowly crush the Mk. 3, where it eventually blew up as Ben Tennyson escaped its destruction as Jetray, leaving Vilgax believed to be dead like the last few times.

In the Vengeance of Vilgax, it is revealed that the Chimerian Hammer Mk. 3 is actually a part of a classification of battleship due to the appearance of multiple similar-looking vessels hovering over the Earth that were part of Vilgax's fleet.

Ben 10

 * And Then There Were 10
 * Secrets
 * Gwen 10
 * The Visitor (Flashback)
 * Perfect Day
 * Ben 10: Secret of The Omnitrix

Alien Force

 * Vengeance of Vilgax: Part 2
 * Primus
 * The Secret of Chromastone (Flashback)
 * The Final Battle: Part 2

Powers and Abilities
The ship is very well-armed, having many lasers and other weapons but its armour is not very effective. In the first episode, Xylene's ship - much smaller - could severely damage it in a few hits. The speed of the ship is very high - it had pursued a smaller size ship of Xylene's without any difficulty. The ship is weaponed with four cluster of four laser turret (secondary weapon), and large, forward gun, targeted by turning the entire spacecraft. It is operated entirely by Vilgax's robot crew. Oddly, it has similar sacs that Chimera Sui Generis have. These may be widows since there are some in the command station.

Ben 10: Protector of Earth

 * Here the ship is known as the Merciless and serves as the location of the final battle with Vilgax. It was destroyed when Ben destabilized the Null Void projector and caused the ship to be sucked into the Null Void.

Ben 10 Alien Force: Vilgax Attacks

 * Here the ship is depicted as having a Null Void Projector strapped to the bottom of it, It was destroyed when Ben used Alien X to reverse the Null Void projector, causing to be torn in two as it was being sucked in.
 * Based on all its appearances, there are at least four of those starships in the Vilgaxian navy.