Coal was a young female Dragon living in the annals of Joy Prime. She had been posing as an emissary of the ancient "Saint of the Tower" to extort gems from superstitious residents of Bittsburgh. She attacks Lozenge and company when they threaten to expose her. She was described as being, "black; rough, sooty black, like a creepy whisper in the basement".
She had become addicted to Laughter due to it leaking steadily into her water supply.
She is killed when the giant peek-a-boo cutout of Pinkie Pie activates, shearing off her wings and pitching her several hundred stories into to side of Foal Mountain.