A Myhr'an battle cruiser is a Myhr'an starship, equivalent in size to an Excelsior-class starship.
Typical Myhr'an battle cruisers were armed with disruptors, one of which was located in the forward section. The overall ship design made it appear similar to an Earth shark.
During 2372, the USS Cantabrian had several run-ins with Myhr'an battle cruisers. After the Cantabrian's launch, they responded to a distress call from the USS Koru, under attack by a Myhr'an battle cruiser. After rescuing the Koru survivors, the Cantabrian made a hasty exit. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part One")
The Cantabrian faced three Myhr'an battle cruisers when investigating the disappearance of Starbase Expanse 3 personnel. Again, they retreated. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part One")
Several Myhr'an battle cruisers accompanied the Myhr'an super battle cruiser. These battle cruisers suffered auto self-destruction sequences when their crews' link with an alien force controlling them was shut off. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part Two")
The Cantabrian and USS Aotearoa faced three Myhr'an battle cruisers in the Rhinessa system while trying to rescue survivors in a Myhr'an internment camp. (Star Trek: The Cantabrian Expeditions: "Two Hit, One Stone")
In defending Canaileus Prime from Myhr'an invasion, the Cantabrian successfully fought off a Myhr'an battle cruiser with the assistance of the FNN ship, D'Audney. FNN reporter Kevin Alton rammed the D'Aubrey into the Myhr'an battle cruiser, destroying it. (Star Trek: The Cantabrian Expeditions: "Oh, What a Lovely War")