Blood of the Dragon.
After being released from his inner earth prison, Skullmaster travels to an island where he preys on and deceives some of the native inhabitants into drinking dragon's blood. This transforms them into reptilian creatures that become mindless slaves obedient to his commands. Max, Virgil, and Norman head to the island to stop him and encounter a young native who is stuck in mid transformation because he didn't fully drink the dragon's blood. Together they attempt to rescue the rest of the natives who haven't drank the blood of the dragon.