This is the mushroom head child, Peculiar Mind. It's a combination of watercolors and ink. The inspiration came from an episode of an anime called Fairy Tail. The main characters were hungry, and they foraged for mushrooms. When they ate the mushrooms, a giant one grew on the top of their heads. I already had a bit of an obsession with mushrooms, so why not recreate that? It's on a (roughly) 11"x15" sheet of watercolor paper.
2018 comment: Thank you birthday lady.