The Teuthis are a species of extra-dimensional beings. In 2379, the Teuthis attempted to use their catspaws, the Priatians, to incite civil war in the New Thallonian Protectorate. This event ultimately led to the death of Fhermus and Si Cwan, two rivals in the New Thallonian Protectorate. (NF novel: After the Fall).
They consider a Borg arm to be the most holy of their ancient relics. (NF novel: Missing in Action)