There's a Fungus Among Us

This appeared in my backyard this morning.  My first thought was WTF is that?
Not what it looks like, unless your innocent mind says "why it's a mushroom, silly!"
So, what kind of mushroom is that?  Is it dangerous?
(Those of you who want to make a joke about The Mushroom That Impregnated New York can do as you please, as usual, but this is actually a real question as well.)

Addendum #1: You are no help at all in mushroom identification, folks.  Turns out it's a "stinkhorn," with the totally obvious family name "Phallaceae."

Addendum #2: I sent the picture to the Mushroom Expert for his collection and he (very kindly!) replied:

Thanks for your e-mail. That looks like Phallus hadriani to me:

http://www.mushroomexpert.com/phallus_impudicus.html

. . . but the specimen is a little bit odd, because part of the "egg shell" stuck to the cap when it expanded, which doesn't usually happen. Neat!