Mystery snails are a favorite among aquarists old and new. They are one of the largest aquatic snail species, and they come in a variety of colors such as white, yellow, and black. They are active animals, always crawling around the aquarium searching for their next meal. What makes these animals unique is that they breathe both air and water. They need water to survive and will dry out if they are outside the tank for too long, but they can live for several hours outside of water.