The Wandering Hand used to look like a mixture between a Derro and a Duergar, a creation of the Stone Chiseler to create mines for the ores he needed. That was until his own creator cursed him into a massive wormlike being, but rather than slithering along on his stomach, the has over twenty massive arms that help him crawl along the ground. And the shape of one of those massive hand is the form that his follower's holy symbols take.
The Wandering Hand is a giant, purplish-grey worm that's over a mile long and is about a quarter of a mile wide. He is a fleshy mass that twists and knots, the mere sight of him can make the weak retch. His mouth takes up a majority of his face, and it is absolutely revolting like the rest of him, he can be seen eating his way through nearby ground in his home plane.