Monsters

Breath Weapon (Su): Either a line of acid 5 feet high, 5 feet wide, and 5x5x80 feet long or a cone of slow gas 40x40x40 feet long. It cannot use either breath weapon until 1d4 rounds later. Acid damage 10d4, Reflex half DC 21; gas damage Fortitude save (DC 21) or be slowed for 1d6+5 rounds.

Frightful Presence (Ex): The dragon can unsettle foes with its mere presence whenever it attacks, charges, or flies overhead. Creatures with fewer than 17 Hit Dice (except for other dragons) within 150 feet of the dragon must succeed at a Will save (DC 21) to avoid this fear effect, and remain immune to that dragon's frightful presence for one day. On a failure, creatures with 4 or fewer HD become panicked for 4d6 rounds and those with 5 or more HD become shaken for 4d6 rounds.

Spells: Knows and casts arcane spells as a sorcerer of level 5, gaining bonus spells for a high Charisma score. Can also cast cleric spells and those from the Chaos, Earth, and Trickery domains as arcane spells.

Immunities (Ex): All dragons are immune to sleep and paralysis effects. All copper dragons are also immune to acid.

Spider Climb (Ex): The dragon can climb on stone surfaces as though using the spider climb spell cast by a 5 level sorcerer.

Blindsight (Ex): Can ascertain creatures by nonvisual means (mostly hearing and scent, but also by noticing vibration and other environmental clues) with a range of 150 feet.

Keen Senses (Ex): Sees four times as well a human in low-light conditions and twice as well in normal light. It also has darkvision with a range of 500 feet.