I've thought a snake escaped before (she was actually stolen, but that's neither here nor there) and I saw a trick online with a bird cage - you pry the bars apart just far enough to allow the snake through, and after she eats the mouse she stays in the cage.
I can't attest to it working or not, since my snake was unfortunately never recovered.
PS cool name, I have a cat named Fenrir
Sent from my iPhone using Tapatalk