I recently put fleece as a backing for a quilt. I used French Fuse, a tricot interfacing, to help control the stretch. Worked like a charm. The stretch of the stabilizer is ironed opposite to the stretch of the fleece. It's so light, it can't be felt once in a quilt. I think it might work for a stuffed animal the same. Just test the fleece to make certain it won't melt. Some do.