The Frankfurt Zoo’s White Elephant (1949)
In the days leading up to April 1st, notices appeared in Frankfurt papers informing the public that a legendary "snow-white elephant" from Burma would, for a few days only, be on display at the zoo. It was en route to the Copenhagen Zoo, which was to be its permanent home, accompanied by its Burmese handlers, who were dressed in their traditional robes and head coverings.
On April 1st, over 1000 Frankfurters turned out to see the white elephant, paying a mark each. And they did see a white elephant, but it was a regular female Indian elephant that had been painted white. However, the majority of the audience didn't realize this. They learned the trick later by reading about it in the papers.