that's called a "Pond Snail". It usually comes in on plants or sometimes in the water of fish received. The lay eggs in gel masses on the leaves of plants or the aquarium deco/glass. They are good scavengers IMO, but some folks tend to find them a nuisance. The reason is their ability to thrive if under the right conditions. The right conditions being mainly overfeeding.
Thank you for your help. I was told also that these are Japenese trapdoor snails.The first pic is of the Trapdoor's and the last is the pond's. So now I am totally confused.
Definetly a pond snail. Pond snails are awesome. It is unfortunate that they are so widely thought of as pests, they are extremely beneficial to an aquarium.