This does not include the waving mechanism. I got the mechanism from an old toy and haven’t been able to find individual parts to buy to recreate it. Sorry. ☹
However, you can include some other fun things in it, like a rattle, jingle bell, dog squeaker, etc.

Materials:
yarn (color of your choice)
crochet hook, appropriate size for the yarn chosen
one pair of safety eyes
yarn sewing needle or tapestry needle (optional)
stuffing
yarn markers or different colored string for marking spots

What I used:
Medium weight yarn (cream colored) (1 pound skein)
5.00 mm/size H crochet hook
12mm safety eyes
spare pieces of string for row markers

Finished Size:
Hat pattern is sized for adults (approx. 23 in head diameter). Estimated time to make: 8 hours.