I made a diaper cover to match the bunny hats that I made. I don't know if it will fit my nephew, I might have to make a bigger size for him.
I used the free Adjustable Diaper Cover pattern, but modified it very slightly by only using one colour for the whole thing and adding a pompom on the bum for the bunny tail.
This is a very simple pattern even for me. I don't crochet much and this is by far the most complicated pattern I have done. It was quick to make and the result is super cute.