What to put in an empty 10g tank

[Nismo89]

I have an empty 10g aquarium 20"x10"x12" and I was wondering what snake would fit in that for about 4-6 months until I buy my stack of boaphiles which will be 4'x2'x18". I'm thinking about getting a corn snake but I've also thought about a bp because they have one at petco that NEEDS a home. Every time I go there it seems to have stuck shed or poop in the cage and they are also feeding it live mice that aren't even as thick as the snake. Anyways I'm open to any and all opinions. I won't be getting the new addition whatever it may be for a few weeks.