A Hammerhead-class cruiser was in service during the times of the Old Republic. Its wreck was found thousands of years later on the planet Mustafar.
At an unknown point in time during or after the Galactic War, during the Old Republic era, the cruiser crashed on the volcanic world of Mustafar. Due to the heavy volcanic activity and evershifting landmasses, the wreck was buried underneath layers of lava, rock and ash.
Thousands of years later, a huge earthquake brought the remains of the cruiser back to light. It was the time of the Clone Wars and the planet was under the control of the Confederacy of Independent Systems. When the wreck was discovered, Neimoidians separatists immediately closely examined it. They were very protective of the crash site and did not allow any Mustafarian the chance to examine the wreckage. No records of the crash were found aboard the ship and no engineer who had examined it could explain why it crashed. Inside the wreckage, the Neimoidians found the deactivated body of an very old assassin droid. When they reactivated the droid, it went on a rampage, killing several Neimoidians and the battle droids that were supposed to protect them. The droid turned out to be none other than HK-47, a rogue assassin droid that had once served Jedi Knights Revan and Meetra Surik thousands of years earlier. The Separatist experts were amazed by the technology used in this droid, but were unable to perform a memory wipe due to its incomprehensible thought matrix. As a solution, the engineers transferred HK-47's memory and thought patterns into a functioning sub-system of the crashed cruiser and took the empty chassis with them. While the Separatist scientists studied HK-47's body in their new droid factory, the droid's AI managed to meld with the ship and took over its operational systems, forcing the scientists to seal up the ship and disconnect its uplink. The cruiser was left abandoned, leaving valuable salvage behind.
At the time of the Galactic Civil War, a gang of Salvage bandits had moved onto the site to claim any valuable piece of technology for their own. They were very intent upon keeping everyone else away from their prize. Twenty years after the defeat of the Separatists, in 1 ABY, a group of spacers working for Mensix Corp explored the wreckage of the Hammerhead-class cruiser to salvage power rods and to search for valuable technology. HK-47 thus used the systems of the ship to contact and trick the spacers. HK-47 instructed the spacers to aid in transferring his artificial intelligence from the ship to an abandoned research facility nearby, and then to an old Separatist droid factory on Mustafar. This eventually allowed HK-47 to be reunited with his body and to begin the production of a large droid army.
The wreckage of this Hammerhead-class cruiser appeared in the 2003 video game Star Wars Galaxies, a massively multiplayer online roleplaying game developed by Sony Online Entertainment and published by LucasArts, prior to its closure on December 15, 2011. The wreckage of Hammerhead cruiser was added to the game with the release of the expansion pack Trials of Obi-Wan on November 1, 2005. The ship could be found on the central island near the Central volcano and was surrounded by many Salvage bandits. It was part of a quest surrounding the assassin droid HK-47. During this quest, the player entered the ship and accessed the ship's computers to talk to HK-47 and transfer him to the droid factory where he was eventually reunited with his body.