Big Fats Dynamo has turned himself in just so he can be the first person to break out of Rebel's Island prison.The warden is left no choice, so he sends for Atom Ant.
Dr. Crankenshaft M.D.(Mad Doctor) has created a monster to help him conquer the world.Everything goes his way until they rob a bank and Atom Ant is alerted.
Lured by a phony letter about Doctor Strangebug's reform, Atom Ant goes straight for the lump of sugar on his time machine! Sent back to the days of King Arthur, Atom Ant tames the dragon and is dubbed "Sir Atom Ant".
With no trouble in the world today, Atom Ant goes back to the days of old where the evil black knight will take over the until now happy kingdom, unless someone is foolish enough to joust with him.
When a wagon train of ants is surrounded by a red ant tribe on the western plains, the lone ranger, Atom Ant, responds to their cries for help. Chief Big Deal arranges a contest of strength between Atom Ant and his son, Big Moose.
One night, during a violent thunderstorm, Tyrone the Tyrannosaurus comes back to life in the museum and goes out terrorizing the city. Although Atom Ant tries to reason with Tyrone, they head for the ballpark and an all-out battle.
A mouse, trapped by a cat, writes a desperate plea for help to Atom Ant, who shows the cat that ants are not insignificant little creatures to step on. Just as Atom Ant thinks his work is done, he must save the cat from the dog next door.