The Myhr'an super battle cruiser was a large Myhr'an starship, of a similar configuration to a Myhr'an battle cruiser but nearly 800 meters long.
In 2372, the Myhr'an super battle cruiser was a part of the Myhr'an fleet accompanying the Myhr'an planet killer. Like other Myhr'an ships, the super battle cruiser was equipped with a cloaking device, used to escape after the Myhr'an defeat at Canaileus Prime. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part Two")
Later in that same year, still under the command of the Myhr'an commander, the super battle cruiser attacked and crippled the USS Cantabrian, with a boarding party kidnapping Cantabrian officers Captain Noah Wrightson, Elizabeth Singh, Benjamin Caldwell and Daniel Radke. Helena Bourget was gaining safe passage on the cruiser at the time.
Bourget freed the quartet and escaped aboard a stolen Starfleet shuttlecraft, and Caldwell and Singh disabled the transmission controlling the Myhr'an clone population on board as Wrightson and Radke fought the Myhr'an commander. With the ship under no one's control, the Cantabrian, assisted by the USS Aotearoa, delivered a death blow, beaming their four crewmembers back before the Myhr'an super battle cruiser exploded. (Star Trek: The Cantabrian Expeditions: "Deceptions")