Being pets are animals like horses (animal, vegetable mineral...yeah animals), players should need to bring them to the stable where they can be stored permanently (like a boarding house), OR chose to keep it in inventory and run the risk of deleting it. After it is stored it can be accessed by all characters on an account at whim. Instead of wasting inventory / bank space, they are always there at the stable. a character just need walk over and talk to the stable master and choose which pet to take....they can log out with that toon, log in with another, and grab the same pet if they wanted.