Revenge of the one trick pony

Everybody thinks that the "ponies" in Xander's magic show are made to look the way they do (like zombie ponies) with tricks and make-up, but the eccentric billionaire Russ DeVon knows what they are (the unicorn part, at least) because when Russ was nine he discovered Pegasia, and was kicked out for trying to steal a baby unicorn--and now he will stop at nothing to get back there.