Grebnedlog was the captain of the Pakled ship Mondor, who seemed helpless but kidnapped Geordi La Forge to steal Federation technology.
Grebnedlog commanded the Pakled ship Mondor in Samaritan Snare. The Pakleds appeared slow and clumsy, and their ship seemed disabled, so Riker agreed to send Geordi La Forge across to help with repairs while Picard was away for medical treatment.
Once La Forge was aboard, Grebnedlog took him hostage and demanded the Enterprise's weapons technology. Riker and the crew turned the Pakleds' gullibility against them with a staged display of a fearsome weapon, and Grebnedlog released La Forge. Christopher Collins played him.