Another fine example of the other end of a caterpillar ... I think. It was moving towards me shortly before I took the photo, so either they have a reverse gear or it flipped around just before I figured out camera controls. Maybe a Tussock Moth caterpillar, it is a shock wig of white hairs with a few "angry eyebrow" spikes of black sticking upwards along with black short tufts along the spine. There's no visible head on this end, maybe it's ducked down, or we are simply at the wrong end.

Tiger Milkweed butterfly caterpillar on the underside of a milkweed leaf. I think the head is on the left, but it hasn't started eating anything yet. Both ends have black arched antenna looking things and of course the whole body is alternating strips of yellow, white, and black. The feet though. Have you considered the functionality of a caterpillar foot? They have quite a few, 10-ish for this one, and there don't seem to be toes but they must have some mechanism inside those moccasin shaped stubs for secure anchorage since, like this one, they are often upside down and only so many of them are touching the leaf during locomotion.