The Tanthior was a naval vessel of the Hammerhead-class cruiser type. It served the Galactic Republic during their conflict known as the war with Zakuul.
During the Zakuulan Eternal Empire's conquest of the galaxy, the Tanthior received orders to reinforce a Republic fleet engaging the advancing Zakuulan forces. However, the designated meeting location had been revealed to the enemy, and the ship sustained damage en route. This resulted in the destruction of a portion of its forward structure and injuries among the crew. These issues, coupled with diminishing fuel and supply levels, fueled discontent that ultimately led to a mutiny. The crew successfully took control of the food preparation area and weapons storage, deposing the original captain. Subsequently, the new "captain" made the decision to sell the vessel to the Hutts. At a later point, the hijacked warship was repurposed for transporting dangerous animals. During one particular voyage, the poorly repaired hull gave way, allowing at least one of the creatures to break free, killing the crew and causing the ship to crash on the planet Onderon, where it remained abandoned. Sometime during the events of the third Galactic War, the wreckage of the ship was located, and the Eternal Alliance's commander later managed to retrieve the ship's recorded data.
The Tanthior is featured in the repeatable side quest "Combing the Wreckage" within the Star Wars: The Old Republic Onslaught expansion. The player character's objective is to recover the ship's data logs. It is the first time a Hammerhead-class cruiser actively serving during the game's timeline is shown. Before this, the only Hammerhead that had been seen was the Endar Spire, which had crashed more than three hundred years before the game's story. However, other Hammerheads are shown in active service in the novel The Old Republic: Annihilation, which takes place during the Galactic War. Additionally, ships of this classification appear later in both the comic Knight Errant: Aflame 2 and the novel Darth Bane: Path of Destruction, both of which are set over 2,500 years later, implying continuous use of the design.
The references to the damaged hull section were likely inspired by an observation made to creative director Charles Boyd on Twitter, pointing out that the ship appeared to have two top halves. He also mentioned that the ship probably had a modified set of weapons.