We picked up a pink foam visor from the craft store for $1 and some self adhesive foam animals for around $3 for about 50 of them. They also carry a wide variety of foam letters, shapes and animals in a bunch of different colors so you can personalize this any way you like. We choose a pack of animals that contained monkeys, frog, cats and dogs which just so happens to be her favorite animals.
I let her select the animal that she wanted to put on, then I pulled the back off to expose the sticky side and let her place it on the visor where she wanted.