In 2376, The Doctor was sent to the Alpha Quadrant to treat Doctor Lewis Zimmerman for a fatal virus. Doctor Zimmerman believed The Doctor to be obsolete and therefore refused treatment. The Doctor tried more creative means and downloaded a Tarlac female template in order to alter his appearance, and went to Doctor Zimmerman as a masseuse. In that guise he attempted to secretly diagnose Dr. Zimmerman's illness. Dr. Zimmerman discovered the ruse and realigned The Doctor's matrix. (VOY: "Life Line")
Background information Edit
According to Star Trek: Insurrection text commentary, the Tarlac make-up and head prosthetics were inspired by lions, suggesting that they could be a feline species. Also, like the Ellora, the T-zone of the Tarlac actresses did not have prosthetics in order to utilize their natural beauty.