Tiddler is a very fidgety fish. So much so, that when his mother has had enough, she sends him out into the sea to swim, "Watch out for the Big Fish," she warns. Tiddler flips and glides and swims faster than a rocket. He comes across several sea creatures before his curiosity gets the better of him and he enters a big, dark cave... When Tiddler hears a loud snap, and everything suddenly goes dark, he realizes he is in the belly of "the Big Fish"! Now more fidgety than ever, Tiddler jumps and bumps, tumbles and turns inside the belly of the fish, causing more than a bit of a disturbance until — BURP! The big fish has had enough of Tiddler.