mr. potatohead is based on technology developed for roz in DCA's monster's inc ride. they had don rickles record all the lines and he has a CM that operates him that can choose from a series of phrases and piece them together to talk and address certain guests in the queue based on age/gender/clothing type of thing. unfortunately his pieces are rather long (particularly when he breaks into song) so he's not quite as fun as he could be. conversely, roz addresses each car as it passes by her so she has a shorter time window to address particular guests and she's not entertaining a crowd either.