Spike is one of the lead characters of My Little Pony: Friendship is Magic. He is a purple baby dragon with green spines. Canonically, he is depicted as hard-working and loyal, but naïve and childish. He has been Twilight Sparkle's companion and research assistant every since he hatched, and is the character most able to deal with her mood swings. He acts as scribe and fax machine to the Mane 6. He has a strong crush on Rarity, which she is perfectly well aware of.
Characters based on the design or character of Spike should be given the category "Spike".