The ChR Harrier was Z1-class Romulan Bird of Prey.
History
In 2286, the Harrier was sent to a planet in Sector 9. There it ambushed the USS Cluster. After its commanding officer Lazar, had killed the Cluster's captain and landing party, it moved in to attack when the Cluster lowered its deflector shields. It inflicted heavy damage on the Cluster, destroying its C deck. However, the Cluster retaliated hard, but the Harrier held. However, the Harrier was forced to retreat when the USS Enterprise-A intervened in its fight with the Cluster. (TOS comic: "Idol Threats")