The stinkhorns probably take the prize for most phallic mushroom family, which is probably why the family is called "phallaceae". This one is a "dog stinkhorn" photographed in Illinois; there's a very similar one called the "devil's dipstick" which is just a little thinner. There can be quite a bit of variation in color - sometimes the dog stinkhorns are very pale white with just a bit of pink near the tip.
It's not only their shape, it's also the fact that they've got a hole at the end which oozes a nasty looking liquid containing the spores. It's easy to smell it from 40 or 50 feet away, and flies just love it - this is how it disperses the spores.
It really doesn't bear thinking about.
Here's another one, this time an "eastern stinkhorn", appropriately named Phallus ravenelli in Latin, photographed in the Great Swamp Wildlife Refuge.
The smell wasn't as pronounced, but the flies were enjoying it anyway.
Other stinkhorns have Latin names Phallus impudicus and Geastrum fornicatum, so you get the idea!