[1] The film is loosely based on the traditional tale "Jack the Giant Killer" and features extensive use of stop-motion animation.

The film reunited Mathews, Juran, Small and actor Torin Thatcher, all of whom had worked on The 7th Voyage of Sinbad.

In the Duchy of Cornwall of fairy tale days, an evil sorcerer named Pendragon rules over giants, witches, hobgoblins and other dark creatures.

Pendragon arrives disguised as a foreign lord named Elidoras and presents Elaine with a music box containing a miniature anthropomorphic dancing jester.

That night, Pendragon peers into the sleeping Elaine's bed chamber and magically opens the music box, releasing the tiny jester.

The creature grows into a hideous giant named Cormoran that the castle guards are powerless to stop as he abducts Princess Elaine.

As Jack and Elaine begin to fall in love, King Mark and his chancellor are concerned over Pendragon's looming danger.

He introduces them to the Imp, a leprechaun imprisoned in a glass bottle by the king of the elves for having crafted seven-league boots from his pot of gold.

The Imp (who only speaks in rhyming sentences) explains that his three remaining gold coins can each grant a wish to an honest person.

When she touches the Imp's bottle, her evil nature causes it to grow hot in her hand and she reflexively casts it into the sea.

The Imp's bottle has washed ashore, and he grants Jack's final wish by summoning a sea monster that kills the giant.

Jack kills him after a fierce battle, causing Pendragon's castle to collapse, crushing Garna and the witches.

[2] Small hired star Kerwin Mathews, director Nathan Juran and villain Torin Thatcher, all of whom had worked on The 7th Voyage of Sinbad.