Bizmatec

Bizmatec was the Glabrezu that acted as the Balor Errtu's Second-In-Command, and was sent to the Material Plane to help Matron Baenre in her quest to take Mithral Hall, while Errtu was still under his banishment.

You can find reference to Bizmatec in the Legend of Drizzt series of books, mainly Starless Night, Siege of Darkness, and Passage to Dawn.