The logic of what you're about to do really doesn't make that much sense. Drinking from a fountain turned you into a cat, so drinking from the same fountain will reverse the changes?
After the little incident with the mouse you're afraid of gradually losing yourself to the growing feline influence inside of you. Of anything, it's at least an attempt to fix what's happened to you.
Sitting up, you focus on building up a power before launching yourself upwards. Your paws slide easily up the stone wall the fountain is attached to and you find yourself perched on the edge of the fountain, balancing on all fours. You adjust your position to be sitting on the edge of the fountain, your tail hanging off the edge behind you.
You reach your front paws down and find yourself laughing inwardly. Cats' round, small paws were made for walking, not cupping water. Wincing at having to perform an action that makes you seem even more like an animal, you reach your head down and look at your face in the water. Your green, slitted eyes and whiskers remind you that right now you look no different than an ordinary house cat. Grimly, you stuck your rough tongue out and begin lapping at the water.