A drawing I did and uploaded onto DeviantArt on Dec 6, 2009.
I'm posting old art that I loved here as well.

Old Description from the site:
I been planning to do this ever since I thought about having an account here!

Ahem.

The Hedgehogs use to be a common species. When Nintendo found these creatives, they decided to feature them on a game as a mock to Sega's Sonic the Hedgehog. Their numbers diminished as the Yoshis got to them. Most of them flee to the caves while others hid elsewhere; they are now on the endangered protection list.

Most Hedgehogs are blue and they all share the same trait of being very fast runners; the reason why Nintendo placed them in their game. Some can vary from having blue quills. This was noted when a (pokemon) trainer confused female pink and green hedgehogs with flowers in their quills for Shaymin. According to the trainer, when they got angry for being pelted by balls, they used "rollout" on him repeatly and went away. Another trait all hegdehogs share is the ability to crystallize. Their quils become sharp, tough diamond-like material and grow to unimaginable size. How big their crystallization can be is still unknown. However, it is known that they use it only for protection from their preditors(yoshis) or as a disquise(since they live in caves loaded with crystals).

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(The rest of the description is in the pinned comments)