It is late Spring when Wally, Jeremy, Shades and Mario are at the La Brea Tar Pits working on a school research project and discover a mysterious tar egg that cracks open to reveal a friendly dinosaur.

Denver follows Jeremy to his job at the supermarket, where he hides in the storeroom and stuffs himself full of potato chips.

Wally borrows his sister Heather's video camera and the starry-eyed kids set out to make a video starring themselves.

While camping at a mountain lake with the boys, Denver is mistaken for a horrible lake monster.

Denver and the kids make friends with a circus owner's son and help him liven up a lackluster show with bicycle and skateboard stunts.