The Chief Poker was one of the residents of Pokes in the Winkie Country of the Land of Oz.
He arrested Dorothy Gale and the Cowardly Lion for speeding when they arrived in Pokes, and brought them to the castle where Sir Hokus of Pokes slept. When the three attempted to escape by singing, the Chief Poker met them at the city gates, intent on recapturing them, but the Cowardly Lion seized the rope he carried and used it to drag Dorothy and Sir Hokus out of the city. (The Royal Book of Oz)