Only had Nagini pull a houdini on me once. I forgot to put the paintbrush in the locking mechanism (instead of a lock, I just slide a stick between it so that the door can't be forced open). I forgot to put the paintbrush in and he got out. Mind you this was the middle of the night and I was dead asleep. I woke up because he knocked his spray bottle to the ground and the clunk woke me up. He had barely managed to get behind the shelf before I grabbed him put him back in and wedged the paintbrush back in.

I haven't forgotten it again lmao.