Hericium erinaceus is my favorite mushroom to find because I seldom find it and because it is so striking. Nothing looks like it except other Hericium species. The other one you might encounter around here is Hericium coralloides, Comb Tooth, which is branched, unlike Lion's Mane which is just one large clump of soft, white dangling teeth. These two were a bit larger than a softball, though they can get larger. Lion's Mane is often found growing on well-decayed logs close to the ground, as these were. Occasionally, I've seen some growing very high off the ground, sadly, out of reach.
This mushroom is good to eat, and it has been shown to improve cognitive function.
Both the genus and the species name mean "hedgehog."