A lion’s tongue is rougher than coarse sandpaper. Its lingual spines or papillae (pics 2,3) make the tongue so rough that if a lion licked the back of your hand only a few times, you would be left without any skin.
https://www.reddit.com/r/natureismetal/comments/qu359z/a_lions_tongue_is_rougher_than_coarse_sandpaper/