I slowly walked into town with a limp, to go along with the plan. They were all still over at the center of town with Princess Luna, so it all went along with the plan.
When I got in range, I started going like "Gruuuuuur. Braaaaaaaaaaains," and with the reaction I wanted, everyone ran in all directions, screaming their heads off. Except for the Princess.
"You can't scare me, though your costume is very well made."
"This isn't a costume."
"It isn't?"
"Yeah. I'm dead, just needed a body for the prank I pulled off... sort of."
"You're a ghost?"
I stepped out of the body, making it fall over "Yup."
"What is your name?"
"Ben."
"And how long has this 'prank' been going?"
"Since this morning."
"Did anypony notice you?"
"Only Pinkie. She was the one to help me unnerve everybody."
"Is that so, Ben?"
By now, ponies began to slowly come out "Yes. I apologize though if I upset you."
"It's alright."
She looked at where the crowd ran "Don't worry everypony! The problem has been resolved!"
As all the ponies came out from their hiding places, Luna looked straight at me.
"We seem to have a special guest here, tonight."
Busted.
While I like the story, it's totally unlike "BEN" to surrender as quickly as he does in this story. And why would Pinkie knowingly mess with a dead body without even the slightest bit of respect for the dead?