Denobulan freighter

The Denobulan freighter was a starship type in use by the Denobulans in the mid-22nd century. 

History
Sometime in or after 2162, a Klingon ship destroyed a Denobulan freighter because it was escorted by a "Human" (Federation) vessel. The USS Rochelle was unable to prevent the loss of the freighter. The event triggered the withdrawal of the Denobulans from galactic affairs and spurred the Federation's investigation of the roots of the Klingon hatred against Humans.