I believe they are called Stinkhorns. Size: 2 -4 in. tall. What to look for: pink to red, foamy-looking stalk, tip tapered, with olive-green slime. remnants of oval 'egg' at base. Habitat: singly or in clusters on soil, humus, wood-chip mulch, or woody debris.
Stinkhorns
Phallaceae
An egg-shaped case resembling a puffball encloses the young Stinkhorn. As the 'egg' matures, the Stinkhorn swells with water and lengthens rapidly- withing the span of a few hours. The top of the mature Stinkhorn is covered with a foul-smelling, spore-containing slime. Flies and beetles attracted to this transport Stinkhorn spores to new areas.
I found this info in my North American Wildlife book.
you can see in the middle 'egg' where it is starting to 'hatch'