The Rashasa was a Tarn Imperial Fleet starship in service in the 22nd century that was operated by the Tarn. Vessels of this type were equal in battle with the Starfleet vessel USS Verdun.
The crew of the Rashasa were members of the Katula circle. In 2163 the Rashasa encountered the Verdun in the Torgu-Va system during the Federation-Tarn War. The two ships caused enough damage that both vessels needed to be abandoned. The Tarn on the Rashasa sent a message to the Tarn Empire that they had destroyed the Verdun and then abandoned ship. Four-Hundred and Eight survivors landed on the planet Torgu-Va. In 2183 they discovered that the Humans had also survived and resumed their war which continued until 2367. (TNG novel: The Forgotten War)