File:Giantess with Baby on Lap (= blackened gypsum ceiling) (Main Cave, Mammoth Cave, Kentucky, USA) (37490216224).jpg

Western Kentucky's Mammoth Cave is the longest cave system on Earth, with 412 miles known and mapped as of fall 2017. The name does not refer to the early discovery of fossil mastodon or mammoth bones here. Rather, the name refers to the immense size of many rooms and passages.

Shown here is the mottled ceiling of Main Cave, the principal trunk passage in the Mammoth Cave Ridge portion of the system. The original bare passage roof was gray, marine limestone of the upper Ste. Genevieve Limestone (upper Middle Mississippian). A crust of gypsum speleothem later formed, some of which has detached. In prehistoric times, American Indians entered the cave, often traveling miles from the entrance. They used cane reed torches, which gave off smoke. In historic times (late 1700s and 1800s), mining operations and cave tours used lanterns that also released smoke. The smoke from these human activities stained the remaining, originally-white gypsum crusts a dark gray to black color.

In this stretch of Main Cave, the differentially blackened cave roof is called "Mammoth Cave Menagerie". Early tour guides assigned names to some of the distinctively-shaped black crusts. This is "Giantess with baby on lap" (or "Giant's widow with baby on lap").

Early descriptions of the Mammoth Cave Menagerie refer to wild cats, buffalos, monkeys, anteaters, a mammoth, and Barnum's fat girl.

Seeing patterns that don't really exist (whether sincerely or in jest) is called pareidolia.