Share on Facebook Share on Twitter Share on Google+ Officially it is only Tuesday, but yesterday with a special episode SpongeBob was already thinking about his twenty-year anniversary. All of the SpongeBob Squarepants voices made their appearance in the one-hour special. But they didn’t just talk into the figures, they could also be seen as themselves. And that wasn’t the only thing: David Hasselhoff – who also played in the SpongeBob films – also returned to the special. The special episode marks the start of a whole festive year for the famous Nickelodeon sponge, which has been shown at the children’s channel since 17 July 1999. Various celebrities also congratulated the iconic cartoon character with this special milestone.