S1E43 : The Revenge of the Daltons

Lucky Luke catches traveling performer Otto abusing his hypnotizer skill for theft. He's jailed with the Daltons, who convince him to escape together, form a robbery gang and take revenge on Lucky. Otto hypnotizes a whole town, but Lucky remembers some cancel and other commands. Otto resorts to hypnotizing his own side, with weird side-effects, and Averill learned the skill.