Breath Weapon
A creature attacking with a breath weapon is actually expelling something from its mouth (rather than conjuring it by means of a spell or some other magical effect). Most creatures with breath weapons are limited to a number of uses per day or by a minimum length of time that must pass between uses. Such creatures are usually smart enough to save their breath weapon until they really need it.
Using a breath weapon is typically a standard action. No attack roll is necessary. The breath simply fills its stated area. A breath weapon attack usually deals damage and is often based on some type of energy. Breath weapons usually allow a Reflex save for half damage (DC 10 + ½ breathing creature’s racial HD + breathing creature’s Con modifier; the exact DC is given in the creature’s descriptive text). Some breath weapons allow a Fortitude save or a Will save instead of a Reflex save. Breath weapons are supernatural abilities except where noted. A creature is immune to its own breath weapon unless otherwise noted. Creatures unable to breathe can still use breath weapons. (The term is something of a misnomer.)