This is a tiny eastern red-backed salamander (Plethodon cinereus) that lost its tail and survived. I found it in the woods this morning. Unlike the previous one featured in this post, this one is a "lead-backed" morph. It probably lost its tail to a predator and will eventually grow a new one.
This salamander and another lead-backed morph with a full tail that I found later (they are very common around here) did their best to discredit my claim in the previous post that these creatures are slow and sluggish and never run away. They were energetic, agile and determined to get away from me as quickly as possible.