Bizarre crossover idea

[lydia_petze]

I have a Harry Potter t-shirt that has a picture of Harry alongside an excerpt of Mr Ollivander's dialogue; "...holly and phoenix feather, eleven inches...". Lucy just misread it as "Holy phoenix feathers", which immediately sounded to both of us like something Robin would say; "Holy phoenix feathers, Batman!!" (snerk) Surely this could be worked into a crossover...