There are a number of mushrooms called “stinkhorns”; this one is pretty commonly found around here. The brownish slime is actually the spore-bearing material and it has an irresistible scent (at least for flies and such) that draws insects to it. The insects disperse the spores both on their bodies and through their stomachs.
Although I’m calling this the Dog Stinkhorn, it could easily be the Elegant Stinkhorn, Mutinus elegans. Corrections are gratefully accepted!
This picture was taken August 26, 2011, in Green Lane, Pennsylvania, USA, in a hardwood forest.
Here are a couple places to find more information: