Mr. HaHa is a doctor as to stoped Dennis has the Hiccups he Appeared in the two episodes, "Soap Box Cart" and "Dennis's Hiccups" when he stopping Dennis laughing and was to been to have stoped laughing and hiccups and stop it and he was try to stop the hiccups and his plan has to been stops the hiccups dennis has cant have hiccups to stop and he goes to the movie and was trys to trying to stop dennis gots the hiccups and make it stoped his hiccups as been cant does our hiccups and was to trys to stop it and has trying to make his hiccups go way he was Voiced by Matthew Walker