This morning's warm-up sketch.

I had to use his lanky adolescent design as a base - every attempt to anthropomorphize his usual heavy-bottomed design ended up with Spike looking as either a kid, or a femboi.
Even now I'm not entirely satisfied with the results... I like the long tail, but while the green claws make sense biologically by matching his spines' color, they look definitely tacky.
I'm also having a hard time coming up with an interesting clothing style for him. I'd complain about the lack of clothes in canon, but I did find a good clothing style for every other anthro MLP characters, so... ^^'

Spike © Hasbro
Art by  ethanqix