Hissing green acid drips from the fanged maw of this black-scaled, horned dragon.
CR 3; Size Tiny; Hit Dice 4d12
An ancient or older black dragon can use its breath weapon to create an acid pool as a standard action. This acid pool has a radius of 5 feet per age category of the dragon. When an acid pool is created, anyone inside its area takes an amount of damage equal to the dragon's breath weapon (Reflex half). Any creature that starts its turn touching this pool takes damage, but can make a Reflex save for half. Each round, the total damage dice of the pool is halved until the result would be less than 1d6. The acid pool floats on water, and deals damage to anything on the surface.
At old age, a black dragon's bite deals an additional 2d6 points of acid damage. An ancient dragon's damage increases to 4d6, and a great wrym's to 6d6.
A great wyrm black dragon can use this ability three times per day. It works as a mass charm monster spell that affects only reptilian animals. This ability is the equivalent of an 8th-level spell.
Once per day an adult or older black dragon can stagnate 10 cubic feet of still water, making it foul and unable to support water-breathing life. The ability spoils liquids containing water. Liquid-based magic items (such as potions) and items in a creature's possession must succeed on a Will save (DC equal to the dragon's frightful presence) or become ruined. This ability is the equivalent of a 1st-level spell. Its range is equal to that of the dragon's frightful presence.
A young or older black dragon gains the constant spell-like ability to speak with reptiles. This functions as speak with animals, but only with reptilian animals.
A black dragon gains the following spell-like abilities, usable at will upon reaching the listed age category.
A very young or older black dragon can move through bogs and quicksand without penalty at its normal speed.
A black dragon can breathe underwater indefinitely and can freely use its breath weapon, spells, and other abilities while submerged.