@Mooncalf  
Headcanon accepted!

…you’re really trying to apply logic to Pinkie Pie? For all we know, her bouncing around everywhere could be attributed to the possible fact that she might be made of Flubber.

She also have a evil twin sister…  
 
…but that s for an other day

Not just Granny Pie; I headcanon Surprise as Pinkie’s birth mother, an ex-Wonderbolt either KIA or retired far away after leaving Clyde, who later married Pinkie’s stepmom Susan Rock Pie and produced straight-haired half-sisters Inky and Blinky.

This is from that comic, isn’t it?

It’s one of the effects of a mixed heritage. A pony will always default to one of the three specific breeds (alicorns are special) but carry the genetics, which is why earth ponies like the Cakes can have unicorn and pegasus babies. However carrying strong genetics for a breed other than our own expresses itself in other ways. Pinkie’s pegasus genes makes her a natural flier in all ways but the most important one, while Fluttershy’s earthpony genes allow her to commune with animals and treat butterflies as though they were clouds. Rarity’s magic ability to dowse for gems may indicate an earthpony heritage, particularly since her father may be one.
 
Conversely, the more ‘pure’ a pony’s bloodline is, the stronger their affinity for traditional abilities: unicorn magic, pegasus flight, earthpony nature. Twilight Sparkle, Rainbow Dash and Applejack have had very little ‘mixed blood’ in their family trees.
 
Before the unification as shown in “Hearth’s Warming Eve”, the three breeds kept separate and pure, but after they started coexisting, relations got mixed up. Today, most ponies have some degree of mixed heritage, and only a few very isolated clans claim to be perfectly pure.

She’s really energetic. She has as much sugar in her blood as we have haemoglobin.

Kinky thought this and made an entire comic around his headcanon. :j

Nah.
 
Granny Pie was some sort of epic pony on par with Starswirl the Bearded, responsible for the creation of 7 countries, the destruction of 4, the architect of Canterlot, partner to Daring Do, and assistant of The Doctor twice.

This headcanon has been around for a while now.