The gang throws a huge circus party for their 1000th episode, with special guest Bibo (Caroll Spinney): The "Sesamelly Zirkusshow," a circus gala performance taped at "Zirkus Althoff." Remarkable is that Caroll Spinney did not just perform the character to be dubbed later, but also (with the exception of the closing song) provided his voice in German, resulting in Bibo having a noticeable American accent.