Behold! The Spiny Oak Slug Caterpillar:
It was hard not to spot, lounging on my friends parked car, 3/4” long with those brilliant pink and yellow stripes and spikes, as you can see. The slug caterpillars are a family (Limacodidae) of moths and some are indeed smooth and slug shaped, but most have a variety of spikes, spines, and warty obtrusions. Now apparently, most caterpillars have prolegs (hooks or “crochets”), but slug caterpillars are pretty unique in that they employ suction cup “feet”! The spines can also cause skin irritations and burns…
I identified this guy not with my handy dandy bug book, which is never handy. But by image googling, “spiny rainbow caterpillar.” Ah, google.
For further amusement:
Lookout spiny oak slug! There’s a mustache behind you! Slug mustache
Please be sure to check this youtube video I found of a caterpillar “walking.” Includes enticing caterpillar music.