Charlie Brown (pony)
From Equestripedia, the Archives of Equestria!
The Charlie Brown pony was a minor pony who appeared in Friendship is Magic issue 23 on page 16. He was mind controlled to do Cassie's bidding. He was a small, yellow foal with a single strand of black hair. He was presumably the older brother to the Sally Brown pony, though this is unconfirmed.