He nods at the description of mistletoe, half studying their nearby fellow tree enthusiasts, before turning back at the question. Ah! Something he knows

"A seasonal biscuit," he elaborates, "spiced and decorated with coloured icing. They seem to be quite popular. It seems you must make some for Greatfather Winter to thank him for his efforts in bringing gifts. I've seen them used as decoration, too."

Wrathion speaks of the activity with enough distance that it's clear he's never done this himself, but finds it a curiosity. Mortal celebrations are often peculiar and fascinating both.