The hottest new single-topic Tumblr is Teenage Mutant Ninja Noses, which features crude portraits of the famous heroes in a half shell drawn on images of celebrity honkers (including James Franco, Justin Bieber and others).

This is the kind of thing that you probably never would have noticed on your own, but once you see it, it's so obvious -- the human nose looks exactly like the bottom two-thirds of a Ninja Turtle.

A selection of some of the best TMNNs is below. Visit the blog for more noses. Turtle power!