Flamingo Tongue

This is something called a “flamingo tongue.” Click the picture for a life-sized image. It’s a kind of sea slug, maybe three inches long, and crawls about on corals eating, I suspect, everything.
I think it looks more like an uncircumcised penis, possibly with a horrific disease, but then I don’t know what an actual flamingo tongue looks like.
I’m speaking from complete ignorance here. Feel free to ignore me.