I used to get green tree frogs in my toilet all the time! It's really inconvenient when you have to remove them before going as there have been times when I've had up to three in there at once. I love them but I don't want the wet slimy things jumping on my butt out of protest!
When I was a kid my dad had this poster in the toilet of a mans outstretched arm/hand coming up out of the toilet.. this always gave me a paranoid fear of someone/thing grabbing my butt whenever I had to go... damaging stuff I tell you!