Being an Undertaker cosplyer this would be funny. I would wake up laughing (I pinch Ceil cosplayers on the check all the time if I can. lol)
Not that often.... I rarely remember my dream unless it's something transmitting/stressful.
I think I had one in high school about tuxedo mask. And some sort of case from Yami no Matsuei that was stressing be out but that's about it.
My dreams are usually about failed cosplay attempts. lol