Oh yeah, and then there's the fact that Twilight Sparkle bursts into flame twice in Season 1:
|Twilight Sparkle has evolved into Rapidash!|
So that's settled, then. But what about the element of water?
With the understanding that future episodes of MLP:FiM may completely invalidate this, I present you with Kelpies*, the ponies of the sea.
Some times referred to as the hippocampus or aughisky, kelpies are seaponies who usually dwell in the ocean or deep inland lakes. They are a quiet and introspective people who prize the arts above all else. Preferred hobbies are singing, growing coral, or making items from seashells. Their role in the ecology of Equestria is similar to that of the pegasi: they tend to the needs of other aquatic creatures and control the waves and the tides. Unlike the pegasi, who have turned their duties into an industry, kelpies see their role as artistic in nature. They are sculptors, not manufacturers.
Kelpies receive +10% to their Soul attribute and the skills Water Control and Shape Changing (Soul).
Water Control is the ability to manipulate water in order to create or diminish waves and tides. Having this skill grants the ability to breathe underwater, to walk on the water's surface as if it were solid (even while shape changed), and to use the gallop skill to swim.
Shape Changing allows a kelpie to shift between the traditional hippocampus appearance (head and front legs of a horse, with fins instead of hooves and hair, and a seahorse tail) with that of a regular earth pony. Certain aquatic details will remain when shapeshifted, such as small fins, gills, scales, a bifurcated tail, or a mane and tail that are always dripping wet.
|Picture courtesy of LizaPhoenix.com|
While this is basically a "shift between water and land" power, Kelpies who decide to make shape changing their special ability may, at the Ponymaster's discretion, perform other transformations. Changes to coloration and hair style are easy, but at higher levels (and perhaps requiring the expenditure of a Magic point) other abilities may be possible, such as: adhesive skin, sharp teeth, flight and even turning into mist. Consult with folklore for additional ideas.
* Because another name of Kelpies in folklore is Water Horse**. Trololololol!
**Fun idea that is in no way canonical: since most folklore about water horses comes from Celtic mythology, I think it would be hilarious if Kelpies spoke in Scottish, Irish, or Welsh accents. Or pirate dialect! Arrrrr!