Sgt. Frog Episode 33: The Episode We Wanted to Call Tiny Toons or Animaniacs, but Those Were Already Taken!
Episode 33 of 358 of Sgt. Frog, aired November 13, 2004, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Witnessing the merchandising power of the 'Admiral Geroro' anime, Keroro hatches a new scheme to conquer Earth throuugh the creation of his own anime - but the actual process, from storyboarding to artwork to animation, prove far too troublesome and frustrating for the Keroro platoon to handle. They pay a visit to an actual animation studio, picking up the tricks of the trade, and after returning to work, the final product is ready for viewing - but Keroro decides that more work is needed, and returns to the research & development stage (the fact that said final product turned out to be quite horrible isn't even brought up).