A Rock Dog is a rideable enemy that you can find in Volcana or in certain shops, it will attempt to attack the player if they step in front of it by shooting a fireball at them. This fireball can and will detonate any explosive items that it touches including ones on your back.
The skin of this fire-breathing canine is protected by rock-hard plates, hence the name.
It can be tamed and ridden by sitting on it for a few seconds. While riding the Rock Dog you have access to its fire breath, and its fire immunity(fire not lava). The fire breath will cook turkeys much like any other flaming object. In order to use it's fire breath while holding an item or weapon you must hold down and press the whip button.