Mausspots (partially lost animated interstitials; 1970s-present)
Maus is the star of German TV's longest-running show, Die Sendung Mit Der Maus (The Show With the Mouse, otherwise known internationally as Mouse TV). Aimed at young children but beloved by all ages, the show provides a mix of entertaining animated shorts and live-action films answering interesting questions about the real world.
Despite Maus' nearly 50-year run as the show's mascot, broadcaster WDR hasn't been particularly kind to her short interstitial animations, known as Mausspots, which showcase the silly and often surreal antics of Maus and her pals Elefanten (a midget blue elephant) and Ente (a yellow duck).
In recent years, WDR has been showing only the Mausspots from the 1980s and 1990s onward, on the original show as well as the international versions distributed under the Mouse TV banner. The majority from the early years sadly remain lost as WDR refuses to show them on Maus's website or make any plans to remaster them for future airings. This is likely because (as happened to the very early Sesame Street episodes) they're by now different enough in style and tone to seriously bewilder modern young audiences.
However, there are a few of these early Mausspots floating about on YouTube, including the very first one from 1973.