friendly?

Found this moving across the back of my tank. I know it's a snail, but unsure which one. May have came on one of my new nassarius snails. Any ideas?

Cleaning tank we found these… they are moving. Living in the foam / charcoal filter and on/ in the ceramic bag. 2 clowns. Bicolor goby Watchman pistol shrimp pair. I feel pellets and the frozen for the shrimp. Can frozen food come alive? Haven’t put pods in it. First time seeing them. 7...