A boy genius, Freddy Facknitts, invents a time machine that sends Denver and Morton Fizzback into the past and into the middle of a crazy caveman competition called Mammothball.
While camping at a mountain lake with the boys, Denver is mistaken for a horrible lake monster.
Denver follows Jeremy to his job at the supermarket, where he hides in the storeroom and stuffs himself full of potato chips.
The kindhearted Denver rescues one of the boy's arch rivals, Scott, winning his heart and killing his plans to expose Denver to the media in order to gain publicity and votes for the upcoming s...Read More
While visiting Jeremy's Uncle Eli on his Nevada ranch, Denver and the boys attend a local rodeo.
When the boys enter Wally's dog, Rocky, in a relay race for dogs, they also disguise Denver as a dog so that Rocky will perform well.
Wally borrows his sister Heather's video camera and the starry-eyed kids set out to make a video starring themselves.
The boys decide to do a science project on dinosaurs for the school science fair.
On a visit to Aunt Shadie's (Shade's aunt) ghost town, the kids and Denver go on a wild mining car ride while trying to retrieve the deed to the town from some thieves who had stolen it.
Denver practices his magic act for the Charity Carnival. Denver wins and the prize is a rare historical artifact that was mistakenly donated for the raffle. Denver has to run from the shady Bir...Read More
Heather and the boys take Denver to a mountain ski resort.
To help Wally in his predicament with Johnny Price, Denver uses his magic tar eggshell and shows Wally a time in his own life when he was tormented by the Pteranodon, and Wally is able to becom...Read More
Denver, dressed in a Chinese lion robe and headdress, is in pursuit of dognappers in Chinatown during the Chinese New Year Parade.
Casey's movie-star cousin, Lana Lake, invites Casey, the boys and Denver to watch the filming of her latest sci-fi movie, "Leapin' Lizards on the Loose."
The secluded beach where Mario surfs and the kids play is taken over by Rad Tad and his group of Surf Dudes.
Shades had developed a recent interest in karate, as well as in Nikko, the daughter of his instructor.
When Heather's and Wally's parents announce they are expecting out-of-town guests, Heather and Wally are forced to hide Denver at the movie theater, which is rumored to be haunted.
Denver, the boys, and Freddy Facknitts attend a comic book convention. They are dressed as their favorite comic book characters.
Denver and his friends form a rock band called Stone Age Rock. Freddy Facknitts invents a group of robots called The Roborockers. Denver and the gang must rescue the robots when Dr. Funt and Mo...Read More
When disreputable treasure hunters kidnap a valuable dolphin from a marine research facility and use him to locate sunken treasure, Denver dives in to save the dolphin.