Granite Gush

Fountaintail Ponies are like animated statues. They are always made of some sort of stone, such as granite, marble, cobblestone, cement or concrete, asphalt; their bodies aren't limited to stone though, some Fountaintail ponies are made out of lead, copper, brass, steel, aluminum or even silver!
The top part of the mane holds an everlasting spring of water, which is expelled from the Foutaintail pony from it's tail pipe or mane pipe, in the fashion of a fountain (hence, fountainTAIL). A Fountaintail pony's pipes are always made of some sort of metal.
the colour of the water depends on the climate or biome the pony is from. Arctic is light blue, tropical is a rich-ocean blue, desert is a muddy-blue, swamp is blue-green, and so on.
Unicorn Fountaintail ponies have a small pipe in place of a horn. They are only able to perform water and weather type magic
Pegasus Fountaintail Ponies have a sort of sprinkler installed on the sides of their bodies instead of wings.
When a Fountaintail Pony walks, they make the same sound as a rock sliding across the ground, or a ceramic pot falling down a ledge. They can't really walk quietly due to the weight of the material they are made of.
Since Fountaintails are made entirely of stone, they don't have eyes. Nor do they have a cutie mark, because, hey - they were a statue at one point.

Granite Gush by RicePoison