My Little Pony: Friendship is Magic S1 Ep9 "Bridle Gossip"

Twilight encounters the mysterious zebra Zecora, who occasionally visits Ponyville and is rumored to be a witch. When she and her friends display a range of bizarre symptoms the next day, they begin to wonder whether Zecora put a curse on them. Applejack's little sister, Apple Bloom, ventures into the Everfree Forest to find the truth.