when pigs fly

Referencing the fact that pigs do not have wings and cannot fly.

• ""You know, my friend," said Mongan, "that I can't get Duv Laca back unless the King of Leinster asks me to take her back, for a bargain is a bargain." "That will happen when pigs fly," said mac an Dáv, "and," said he, "I did not make any bargain with any king that is in the world.""

• at latter Lammas
• at no time
• in the reign of Queen Dick
• ne'er
• never
• never ever
• not while pussy's a cat
• on the second Tuesday of the week
• sine die
• when Hell freezes over
• when pigs fly
• when two Sundays come together
• when two Sundays meet

• pigs might fly
• camel through the eye of a needle
• a cold day in Hell
• ad kalendas Graecas
• first of never
• never in a month of Sundays
• snowball's chance in hell
• when Hell freezes over