I used this pattern. I did make a couple of changes. I stuffed his wings before sewing them into his body and instead of using buttons for his pupils I cut out felt circles and sewed them on with a small zigzag stitch. I just don't feel comfortable putting buttons on baby toys.
This little guy came together fast. He did turn out bigger than I thought. I didn't measure him before I shipped him off, but I would guess that maybe he is around 7 inches tall.
I made him out of a variety of different materials so that he would feel texturally different to little, exploring hands. His wings were fleece, his back (oops I should have take a picture of his back) was flannel, his front body was cotton and his eyes were felt. Some other great fabrics choices would be corduroy, felted sweaters and knits.
There are lots of patterns of owls floating around. Some are free and some you have to buy, but there is this one, this one and this one just to mention a few!