Gosh, Abbey does this at least once a week! Usually it's just her front legs or back legs slip in when she's changing position on the edge of the tub. Today I was running my bath water and getting ready to get in, and I'm not even sure what she did, but I see her front paws go in followed by her back paws. And she froze. She tried to climb out the side that's just a wall and then she just started meowing so PITIFULLY! I grabbed her as soon as I could, but I was laughing SO hard. She was not a happy kitty, and she didn't come back in for my whole bath.