My Little Pony: Friendship is Magic - Image #452,159

"Okay, trivia time. What wizard did Twilight Sparkle dress up as for Nightmare Night?"
"Starswirl the Bearded!"
"Oh, I'm very sorry, but the correct answer is WHO GIVES A SHIT?"

I love Triumph. Anyone who downvotes this pic clearly has no idea who he is.

Can someone give me context? Who is Triumph?