Spike was initially found by Wysteria and Pinkie Pie in a cave under Ponyville Castle. Waking from a 1000 year slumber, he decreed that Wysteria was the new princess of Ponyville due to touching the mystical flower and set about implementing a number of rules and restrictions for her. She eventually used her new position to both change the rules of what a princess could do and coronated the entire town. Later, Spike served as a guide for Rainbow Dash and Princess Rarity as they searched to find Unicornia to return the lost princess home.
While stuffy and rules oriented to a fault when first discovered, Spike is shown to genuinely care about his new-found friends. Despite this, he takes pride in startling ponies when he first meets them. Spike knows a lot about the surrounding areas and ancient customs but tends to be somewhat forgetful. Unlike his G1 and G4 incarnations, he's never shown to have the ability to breathe fire.