Silver has asymptomatic osteochondrodyslpasia (mutant TRPV4 gene/Fd gene). In short, he is a 'fold'. And other...
I'm discussing also Silver's cat like features.
I already said both Sonic and Shadow have cat-like features, in particular Shadow being a calico. But Silver also has a feature belonging to a certain type of cats.
Because of the cannabis-shaped mane, he may seems without ears at first glance. But, even looking closely, his ears are hard to spot.
Here it is: Silver's ears are unusually set apart, flattened and tiny. Shadow and Sonic have their ears three time larger.
Those kind of ears are typical of Scottish Fold and Ukrainian Levkoy cat breed.
Sonic and Shadow: Straight, upright ears. Silver: short, bending forward ears. It is called a 'single fold' because they're still visible.
My first cat, Goku. She had a mutant TRPV4 gene and had what is called a single fold. Her fold was subtle, the small size of her ears was noticeable. My cat was just a mixed breed, her mum was a regular long haried feral cat, her dad most likely a Scottish Fold, but there is a chance she just developed the mutation on her own.
Now, what is is osteochondrodysplasia? Is what cause the ears to stay small and bend forward. It affects the carlilages of the animal in his whole body. Is actually a form of dwarfism, even when the animal grow large in size (My cat was so large they mistook her as a male) However, if only copy of the gene is present, there is a high change that the symptoms are only cosmetic (small, folded ears). My cat lived 19 years without developing any symptoms of the condition, ear shape aside. However if the condition develops fully (especially in case of a double mutand TRPV4 gene), it causes pain, stiffness and deformed paws and tail.
Apparently, I'm not the only one who thinks Silver is a fold.
Here Silver is drawn with a triple fold. The triple fold is the most requested by cats lover. But, as a former owner of a cat with a single fold, I like to see character with ears similar to those of my cat.
Silver doesn't seems to have other symptoms of osteochondrodysplasia. But he is unusually stiff, he doesn't curl despite being an hedgehog, favoring flight/absence of gravity.
Is SILVER!!!, well, about, more to come - He even has black highlighst around his eyes.
Two Ukrainian Levkoy.
Silver's secondary characteristic:
Sonic and Shadow have long quills, with Shadow having a sligtly fluffier look thanks to his thicker fur and his soft, white spot on his chest.
But Silver literally has a ruff. The ruff is typical of long haired cats. I've never seen a long haired hedgehog. The mutation didn't settle yet (there are, hovever, hedgehogs who have regular fur instead of quills). Silver also has longer quills on the back of his head. Meaning, Silver is long haired.
Silver's fur colour is pale blue, a very diluited black fur and is a 'self', meaning is his only colour, without any spot or pattern (Unlike Sonic who is bi-colour tuxedo and Shadow who is calico/tricolour), with white undercoat (Smokey) well shown in his ruff.
I wonder if Sega did it on purpose. I mean, making Sonic, Shadow and Silver looking like cats, even having unique cats features and giving them some hedgehogs traits, naming them 'hedgehogs''.