Allow me to give you the room-temperature fuzzies:

Are you coming or going? Oh, who gives a peck.

A bit of surfing (thank you BugFinder) seems to narrow this down as Halysidota. Apparently it's a good thing I didn't try to grab it, as the hairs can cause rashes and it may or may not be mildly toxic in its larval form. Otherwise, it's a harmless low-impact broadleaf generalist.