He nods, understanding her unspoken request to elaborate.

"Yes, we call them that because of their appearance and abilities. Passing through solid walls, creating illusions, things like that. There's some superstitions that say that Ghost Pokemon really are ghosts, that they're born from dead humans or Pokemon, but we haven't found any scientific evidence to confirm this." Because as always, as a scientist, he's interested more in actual facts than superstitions and folktales.