The doctor treating Benny Russell in a mental hospital in the false vision sent to Sisko in 2375, who urges him to paint over the story written on his walls.
Doctor Wykoff appears in the Deep Space Nine episode Shadows and Symbols. As Sisko prepares to open the Orb of the Emissary on Tyree, he is suddenly Benny Russell again, the 1950s writer of Far Beyond the Stars, now confined to a cell whose walls he has covered with the story of Deep Space Nine.
Wykoff, who has the face of the Cardassian Damar, is his doctor. Gentle and reasonable, he tells Benny that the stories are his illness and offers him a roller of paint, promising that he can go home once he has wiped them out.
The vision is the work of a Pah-wraith trying to stop Sisko. Benny refuses and goes on writing, and on Tyree Sisko opens the Orb and frees the Prophet that reopens the wormhole.