Tonton Streaming Gilligan's Island (1964) S1E17 - Little Island, Big Gun

A well known crook tries to evade police after a heist and is dropped off on the island by his henchmen to be picked up later after the heat cools down. After being discovered by Gilligan he poses as a doctor but the truth is soon revealed. Now he must keep the castaways at bay and get off the island with his money. Of course with Gilligan on the island this is much easier said than done.