Very first episode - very different to what the show later became. All the well known cast are not here (and did not arrive until 1974). The only recognisable puppet at this point is Zippy, although his voice isn't what we are used to.

Zippy throws a wet sponge at Bungle but hits David by accident. Zippy tells Bungle that a wet sponge is heavier than a dry sponge and David and Bungle find out if he's right.