Klokian's timeship

Klokian's timeship was a small vessel, the size of a Federation shuttle, that could traverse both time and space. The ship was one of many from a fleet of Klokian timeships, in the 39th century. 

History
When Klokian went back in time to hunt omnipotent beings, in 2376, the crew of the USS Phoenix-X came into conflict with him and acquired his ship after defeating him. ("Fight, Part III")

A year later, Klokian joined forces with Meloneus' nephew, Tellus, to steal back the timeship from the Phoenix-X and the go back in time, to 2375, to save Meloneus from being killed. Matt and Shane then stole the timeship and accidentally traveled into an alternate future 2400. There, they were forced to steal enough temporal energy from a future Daniel in order to return to the present. Upon returning, it was decided that the timeship would be kept safe aboard the USS Xena, without Starfleet's knowledge. ("Secret Shuttles, Parts I, II, III & IV")

A few months later, in an alternate timeline, the secrets of the Phoenix-X became public, allowing the USS Voyager to locate the Xena and retrieve the timeship. Janeway intended on preventing the crew of the Phoenix-X from using the timeship to change past events involving the Phoenix-X`s secrets becoming public, but was unable to complete her intended task when she was killed, along with her ship and crew, during a battle with the Phoenix-X. When the Phoenix-X returned to the past, to set the timeline back to normal, they were forced to destroy their counterparts. Soon after, a giant space creature destroyed the now duplicate timeship. ("Phoenix Restoration")

The next year, in 2378, the crew of the Phoenix-X used the timeship to help them enter the temporal sensitive X-Time bubble. ("Avalon Battlefield, Part I")

In 2379, Klokian attempted to steal his timeship back from the Xena, when both the Xena and the Phoenix-X were confronted with a giant temporal rift at Narendra III. Kayl used the USS Angel Wing to chase down Klokian and transport him off the timeship - but the Angel Wing was then struck down by a violent bolt from the rift and the two were lost on Narendra III. The timeship was tractor-beamed to safety.

But to prevent any further attempts at anyone stealing the timeship - its care was given to the Raekwon android, Sub Zero, where he kept watch upon it in 24th century Earth - the last place anyone would look for it. ("Occurrence, Parts I & II")

In 2380, Sub Zero returned to the Phoenix-X with the timeship, to warn about an unknown android threat upon Earth in the 24th century. Through investigation, and time-travel, the crew found that the threat was Trunks, and another android creation of his, named Omega. After destroying Trunks, adopting Omega, and returning to the present - it was decided to leave the timeship aboard the Xena once again. ("The Timeship")