I had me a dream once. Just after I *acquired* this here knife. Only the knife was a bit shinier and I was in an alley somewhere. I dunno, maybe it was Brie or Holsten, someplace like that. Anyways, I'm walking down this alley when I comes across some dumb bloke trying to shortcut his way to market. Like *my* alley is a god-d**ned thoroughfare for just anyone!
Foot Coral. It attatches to a foot like moss, almost gluing itself to an organism. It gets its food supply from the ground, and does not leech off the host in any way. It is not a malignant organism, and is entirely harmless. But it only grows on human feet, and even then, never on the left foot. An organism that it grows on can feel touch through the coral, but not pain. Removal of the coral is painless, but why would you want to?
Texturally, if fells like a dry, non slimy amoeba.