Hornito over an active lava tube from the Pu'u O'o vent of Kilauea Volcano, Hawaii. Spatter of molten lava thrown from a skylight in the tube built this small spatter cone informally named the "cookie monster" by HVO geologists.   Hornito means "small oven" in Spanish, a name that probably was first applied to features like this on active volcanoes in the Canary Islands. U.S. Geological Survey photo by Jim Kauahikaua, 27/09/2002.