Operation 59
A king who loves toys summons the evil scientist Plankton from a television to meet Goku and his friends. Although he is once defeated, Goku sneaks into the castle hidden in a wooden horse. Then he takes over the castle as planned, but one of Plankton's monsters suddenly appears and destroys the ramparts... Source: tezukaosamu.net
EP 16 - Operation 59
1967
Adventures of the Monkey King
In this film, because of complaints from children that Goku is depicted as too much of an eager student, he is instead portrayed as a very naughty modern boy. It then received so many complaints from the PTA about its bad language that it was forced out of the show after all.
(Source: Official Site)