As you can see, the rumors of my death have been greatly exaggerated. 
It's true I've been getting a bit distracted from the Legends of Lore lately, but I have good reason, I promise!
Starswirl's 'Amniomorphic' Spell Decrypted! · 7:10pm Nov 4th, 2014
Honestly the fanon behind the 'amniomorphic' spell has always bugged me, so I went and did some research and found something interesting and rather funny. I'll break it down for you so just stick with me.
Starswirl the Bearded and his amniomorphic spell. First lets break up amniomorphic into its root words 'amnio' and 'morphic'.
'morphic' is one we all should be familiar with as it is a derivative of 'morph', coming from the Greek 'morphē' meaning to form or shape.
That's the easy bit. The confusion comes from the word 'amnio' which could have several different meanings depending on whether you are using new or old Latin or Greek and whether or not you un-shorten it.
'amnio' can be defined via New Latin from the Greek 'amnos' meaning lamb, and the diminutive suffix 'io', making it a little lamb.
This is where the fandom is getting the 'lamb shape' spell idea from. But 'amnio' is the shortening of 'amnion' which is the actual word we want. If we use 'amnion' and define it through Modern Latin (don't ask me the difference, I have no idea) we get something else.
'amnion' via Modern Latin from the Greek 'amnion', roughly means 'bowl'. The literal translation is actually "a bowl in which the blood of victims was caught", but either way it's a bowl so lets just assume it means 'bowl'.
That means a rough translation of the 'amniomorphic' spell would be the 'bowl shaping' spell. Now that may not make any more sense than the lamb spell, but I assure you it does. Just stay with me a little longer.
A person who makes/shapes bowls and other vessels, is called a potter. Now what is Starswirl renowned for? His great beard, and the 'amniomorphic' spell.
So put simply, Starswirl was a 'Hairy' Potter!
There you have it folks! The 'amniomorphic' spell was deliberate! It wasn't a misreading of 'omniomorphic', it was simply the most ingeniously subtle pun ever devised! Mystery solved!
Oh. My. Gosh. I can't believe it. That's fantastic. Excellent Latin work too!
2573902 Thank you. Though the achievement was somewhat lessened when one of my friends pointed out that someone else had already come to the same conclusion. I can't say I'm completely surprised though. After all, it HAS been like 4 years now. Someone was bound to have puzzled it out already.
2573912 Hey, so long as you did the actual work, I'd call it an accomplishment. I'd never thought about it before so you informed me at least!
2573946 I suppose. I tend to think a lot, so I usually have logical explanations for almost anything. It leaves me with a lot of head canon as well. I usually keep them to myself though.
Jossed by the scriptwriter--- though he found the translation amusing.
I believe "amnio" can also refer to an egg, or a part of the egg, or to the amniotic fluid surrounding an unborn or unhatched animal.... implying an "egg changing" spell.
Or perhaps, an egg HATCHING spell? Like the one Twilight used to hatch Spike?
Or more broadly speaking a spell to facilitate the hatching of an egg, sprouting of a seed, or birthing of a child?
Movie Pun intended