Member Animal as a Non-Member Glitch

In order to perform this glitch, you need to at least have a membership that will expire. 

First off, before your membership expires, you must delete all of your animals except the one you want to keep and a turtle. When your membership expires, choose the turtle as the animal you want to keep. This forces the game to make your last animal your land animal. This may also be performable visa-versa.