Talking about ghosts as portrayed in various media, mind you. We see it especially in Nintendo games and media. Emphasis is placed on the tongue, whether we're talking about Gastly, Haunter, Gengar. The Boos from the Mario games don't lick people, but their tongues are sometimes notably exaggerated. Last year's Google doodle had a flash game with ghosts that attacked the player character (a cat named Momo) by licking her.
Even the Ghini from The Legend of Zelda: Minish Cap would attack Link with their tongues. It's one of the stranger aspects I've noticed in Japanese and Japanese-stylized media. Keep in mind, I'm not complaining. It can be hot at times. But it's just a weird thing to associate with ghosts of all things.
Does anybody know if there's a reason for it beyond potential eroticism from the creators? A lot of emphasis is placed on the tongues of ghostly characters and I just think it's intriguing.
Updated by Lekkiyo