Draconic Breath( Races of the Dragon, p. 102)
You can convert some of your arcane spell energy into a breath weapon.
Draconic Heritage (RDr) , sorcerer level 1st,
As a standard action, you can convert an arcane spell slot into a breath weapon. The breath weapon is a 30- foot cone (cold or fi re) or a 60-foot line (acid or electricity) that deals 2d6 points of damage per level of the spell slot you expended to create the effect. Any creature in the area can make a Refl ex save (DC 10 + level of the spell used + your Cha modifi er) for half damage. This is a supernatural ability.
If the breath weapon of your draconic forebears does not deal acid, cold, electricity, or fi re damage, you choose from among the four energy types mentioned above.