It might have something do with finding the Imp in the bottle by that point and displaying magical powers, but still. The witches are eventually destroyed when the castle blows up, having done not one other thing.

They just hang around looking evil and hideous while Pendragon sends easily defeated monsters after Jack.

The one time he sends them out to do his bidding in the entire film, they completely and easily overpower our hero and the entire crew of a ship to carry off Pendragon's evil plans with complete success, the only time in the film any of his plans actually works.

Never Recycle Your Schemes: Pendragon, is known as the Prince of Witches and he surrounds himself with them, hideous monsters with amazing powers.

They don't seem the least bit upset that their captain and at least one other crewman is dead, and they don't hesitate to sail away and leave the captain's young son clinging to a piece of flotsam with Jack.

Mood-Swinger: Immediately after the witches abduct Elaine from the ship and fly away with her, the boatswain and the rest of the crew are suddenly laughing merrily about the prospect of sailing back home to England.

It turns out she was bewitched by Pendragon, though it's never explained how she got that way.

The Mole: Lady Constance, temporarily.

The Mirror Shows Your True Self: Mirrors shows which women are possessed and are 'witches'.

Load-Bearing Boss: The magical energies released by Pendragon's death destroy his castle.

Leprechaun: The 'Imp in the Bottle' who Rhymes on a Dime.

However, he makes up for it by being short and hideous.

The Igor: Garna fits this to a T (abducting women, calling Pendragon 'Master.'), the only thing he lacks is the characteristic hunchback.

Possessed Princess Elaine also has one or two scenes where she cackles in the typical witch fashion, chewing the scenery.

Pendragon's minion Garna is also pretty hammy.

Evil Costume Switch: When someone is revealed to be a witch, they are shown with pale green skin, reptilian eyes, and a ridiculously elaborate dress.

Demonic Possession: Pendragon uses his evil magic to turn women into witches to act as his agents who mostly retain their human appearance until a mirror reveals them for what they are and breaking the mirror exorcises them.

Captain Ersatz: The giant near the beginning looks almost identical to the Cyclops, only it has two eyes instead of one.

film Jack the Giant Slayer (which was originally titled Jack the Giant Killer as well). Not to be confused with the 2013 Warner Bros.

Jack the giant killer movie 2013