Grape Tube Gallmaker (Cecidomyia viticola)
These are beautiful, bright, and healthy specimens of Dog Stinkhorn Fungus, Mutinus caninus, which is harmless to any plants growing nearby. They are pollinated by flies, attracted to the incredible stink of rotting meat that these fungi produce. They are quite startling, but harmless. They will disappear quickly.
The Grape Tube Gallmaker makes its galls on grape leaves, and is harmless to the plant.