The Romulan admiral who met the Enterprise in the Neutral Zone to carry out the extraction of the spy known as T'Pel.
Mendak is a Romulan admiral commanding the warbird Devoras. He meets the Enterprise inside the Neutral Zone for what is supposed to be a secret diplomatic contact involving the Vulcan ambassador T'Pel.
In Data's Day, Mendak plays along with the staged transporter accident that makes T'Pel appear to have died while beaming over. When Picard returns and confronts him, Mendak openly reveals that T'Pel is a Romulan agent and summons additional warbirds, forcing the Enterprise to withdraw. His calm, mocking manner leaves Picard with no option but to retreat.