Immortals can never have creature abilities, although creatures can have disciplines (although they don't "gain" disciplines...they start with them.
Note: All characters summoned in the game are either creatures or immortals. The two types together have a large influence on strategic game play. More on that later.
Back to creature abilities. Creature Abilities include breath weapons for dragons, web attacks for spiders, and a whole range of different abilities specific to each creature.
Here are some samples (poison stinger/flying/earth expansion/fire breath.
Creature Abilities are used like spells as well.