Each dragon has a set of magical abilities unique to them. To use them, you'll need to gather Magic tokens, which can be found by stopping on Magic spaces or in Treasure chests. Spells can grant you extra movement, help you out in combat, and completely turn the tide of the game - don't forget about them! You don't start the game with any Magic tokens, so try and plan your route to pick some up from the Magic spaces whenever the opportunity arises.
Every dragon has two Standard spells and one Ultimate spell. Casting a spell counts as one action during your turn, unless the spell specifies a different time to use it, such as during combat. You can cast each of your standard spells up to once per turn, but you can only cast your Ultimate spell once in the entire game.
See each dragon's page for their list of spells.