As we understand it, there
As we understand it, there are many white caterpillars in the tiger moth family (many of which are called woolly worms or woolly bears). For example, a yellow woolly worm (Spilosoma virginica), also called the Virginia tiger moth, can appear in a white caterpillar phase. For photos of the various colors that this caterpillar can be, see: Although folklore focuses on the banded woolly bear, which does not have a white phase, there are weather sayings related to pale or white woolly bears as well. Some say that pale woolly bears mean that a mild winter is expected, but white woolly bears mean that lots of snow is coming.