It's super easy to make little "human" beds for them. My kids all have them and their blankeys. All you need is a foam block, some material, and some double sided tape. If you want to make a little pillow to go with it you will also need thread, stuffing and a sewing machine or hand-sewing skills and patience(neither of which I have, haha).
You cut your foam block to size, then cut the material to the right length to tuck under the "mattress", use double sided tape to stick the tucks to the foam. I like this method instead of sewing as it's easily removable for washing. If you can wrap christmas presents, you can make this bed ^_^.
For the pillow, it's pretty simple if you know how to use a sewing machine, just cut the fabric to the size you want, sew it shut on three sides then stuff it, fold the open end in for a nice finish and sew over it. You can get all these materials at Walmart and it'll cost you under $20 for multiple beds!