Image imported from derpibooru 
Original Description:
 
Decided to try and redesign Gilda (and by extension, griffons in general) just a little bit, and I decided I liked some of the sketches enough to finish and post :)
 
 
See, in my previous griffin art, I’ve drawn them with their wings in between their front-legs and back-legs, just like how I draw pegasi’s wings. For pegasi this design makes sense; they were horses which just had wings plopped onto their backs. But griffins -or at least, my griffins- weren’t made like that. They were raptors who had their tail replaced with the hindquarters of a large cat. And birds’ wings obviously go in front of their legs. So the only way for their wings to later move behind their front legs is for the limbs to… somehow switch places? Which is possible, this is all magic after all, but I actually like it more if they are different from pegasi.
 
This change to the placement of the wings changes a few more things to the design too. But before I talk about those, I need to point out that this means that a griffon’s front legs are derived from hindlimbs. Where pegasi have two sets of forelimbs (front leg, wings), griffons have two sets of hindlimbs (front legs, back legs), and thus, two pelvises. Though, I imagine after all this time since their creation, their front pelvis don’t look very much like a normal pelvis any more… But anyway; put a hoof of their shoulders? That’s actually knee. Grab their elbow, that’s a heel. You’re gripping toes when you shake their “hands”. Fun!
 
Anyway, back to changes. Since they’re a cat-butt stuck to a bird, they’re really bottom-heavy. For their wings, what would on a bird be relatively close to their center of gravity, is really far forwards on this body. So to move the center of gravity forwards, I tried to move their front legs forwards a bit. Now, I can’t actually move their “pelvis” forwards that much since their wings are in the way -~~but I can shift the actual leg’s position. So I extended their femurs to push their knees forwards and to the side of their chest so their legs are under their wings, rather than behind them. This means that their knees are placed outside their wing chest muscles and gives their front profile a decidedly, uh, wide look compared to ponies. I decided to push their “heels” in under them though, so their legs are more under their body and not splayed out on either side.
 
They are still much too bottom-heavy though; to fly vertically they’ll need abs of steel. Or, something that provides lift for their hindquarters. Like a feathered bird-tail –as flying speed increases, the fan-shape pushes against the air and provides lift. So that’s an option. Except, I wanna have the cat tail :[ So I did this, hybrid thing, where the tail starts with a wide base for feathers to attach to, before tapering to a thin normal cat-tail :) I put the tail feathers on each side of the tail, with a split in the center –I originally actually put a full tail, with some feathers just laying on top of the cat-tail. But then my brain just kept interpreting it as two tails stacked on top of each other?? Plus, the feathers on top of the tail wouldn’t really… do anything except be pretty (which is a perfectly valid reason for their existance). So, split tail it is :)
 
 
Other things that aren’t related to their wings… I’m trying to figure out what the hay is going on with their mouths. Cause in the show, they have teeth. The entire point of having a beak (okay, not really, but one of the points at least) is that it weighs so much less than teeth. So I could do something like give them a set of teeth inside their beak –but what would be the point? The beak is already made for cutting, biting, ripping food apart, etc. Anything like, say, sharp canines feels superflous. So evetually I decided to give them molars at the back of their mouths. The logic is that originally, when they were obligate carnivores, they used them for breaking bones to get the marrow. Since then they’ve evolved to be omnivorous (intelligence -> cooking food -> more energy per food -> roots, tubers etc easier to catch than prey -> being able to eat your greens is good for survival actually. In my nextgen ‘verse almost all sapient species fall on the omnivore side of dietary restrictions), and the previous crunch-bone teeth were used for grinding plant matter too.
 
But, yeah, as the text says, the skull is just a very quick attempt at figuring out how this mess looked on the inside. Don’t use it as a reference ;P
 
 
And lastly, a change unique to Gilda; her actual given name is “Grizelda” now, she just goes by Gilda as a nickname, because I think it’s fun. Last name Gruff, because I headcanon that the reason “Granpa” Gruff is everyones grandpa, is that he tends to just… adopt every griffon orphan he comes across. He acts gruff and annoying, but has a real bleeding heart underneath the surface that makes him take in each annoying sniffeling grifflet he sees. Gilda was one of them, as was Gallus and Gabby, and she chose to add his name to her own as a sappy pony-esque (her words) tribute to him after he passed. Sidenotes; the scene where Gallus looks in on Gilda, Gruff, Gabby and Gavin (small grifflet) through a window is just a few days before Gruff sees and takes him in. Gallus leaves for Twilight’s school just a few months later, hence why he at the time still feels like he doens’t fit in nor have a family in Griffonstone. Also, yes, this means that Gilda is his big sis. She’s the big sis for a lot of griffons actually, and tried her best to visit and look after them after Gruff passed. Gallus is the easiest to see, and therefore the one she’s closest to, since he also lives in ponyville :)
 
Misc. notes:  
Bullet; Yellow You can see the difference in where their wings attach and how their chest muscles are placed in the comparison/smooch between Fluttershy and Gilda :]  
Dot Bullet (Dark Brown) ~~ F2U! As you can see from the naked Gilda, all of a griffon’s bulk are made from 90% feathers. Like all birds, their roundness is a lie.  
Dot Bullet (Brown) - F2U! The tiny text already states is, but to be clear; Felix’ wings still attach behind his front legs, pegasi-style. His front legs are modified griffon front legs though, so they’re also technically modified hindlimbs. He’s basically a pile of different bodyparts held together with shoestring, gum and chaos >:]