Spells are occasionally given for free, but are normally obtained through an in-app purchase. New spells become available at levels 11, 12, 20, 31, and 61. Do not use spells until you go through a level at least once in order to learn which ones will be most useful. You can only use spells a limited number of times. They cannot be used during Boss battles.

Spell	How to unlock
Golden Duck	Causes Golden Ducks to rain down. They are heavy and will fill the entire level.
Frost	Freezes all blocks into ice. Consider using this when you have at least one Blues card remaining and have to deal with difficult stone blocks.
Hot Chili	Turns a random pig into a bomb. Consider using this on a single remaining difficult pig, or when all the pigs are grouped together.
Pig Inflater	Inflates all pigs until they explode.
Mighty Eagle	Homing shot that destroys everything in its path.