Bert

Bert is the best friend of Ernie and a yellow-coated, black-maned and black-eyed earth pony. He has a...distinct unibrow and wears a sweater and green pair of pants.

He has an origin story now.

Toys
Bert was revealed as a one-of-a-kind toy to celebrate Friendship day. He was paired with his best friend, Ernie.
 * Friendship Day set
 * Year: 2015

It probably doesn't need to be said, but he's based off from