I found a bug awhile ago on how to get much larger than the actual scale. You don't keep collision though. (I'm not sure if this is how it went?) I mounted a 5x5x5 player to a 0x0x0 ball.
Yeah, I've seen this happen.
I was finding out some mount points by mounting a tank turret to myself. When I tried mounting it to a non-existent point, it began to grow whenever I moved.