Go to the grocery store and get some Hormel "Compleats" meals for about $2 each. Eat the food and run the plastic container through the dishwasher, then use a pair of sturdy scissors to cut an access doorway so your snake can get under it. If there are sharp edges at the cuts just use an emery board to smooth them out. They are perfectly sized for a baby snake and when flipped over the "top" of it will hold a few tablespoons of water so your baby can stay nice and humid without lying on wet paper.

Once the snakes get larger the rectangular plastic containers that some of the Ramen Manchurian meals come in also work as hides.