Trebius Niger was an ancient Roman author and statesman of the second century B.C. He was a companion of a certain Lucullus and in 150 B.C. was the proconsul for Hispania Baetica. He wrote a large work on natural history which was used by Pliny the Elder.
As a fish
Pliny credited Trebius for his work on ichthyology. However, this acknowledgment was misinterpreted by Thomas of Cantimpré when he wrote his Opus de natura rerum, using Pliny as a source. As such, Thomas records a nonexistent fish called the "black trebius" (trebius niger in Latin). He is followed in this error by St. Albert the Great in his monumental treatise De Animalibus.
References
Trebius Niger Wikipedia(Text) CC BY-SA