I have added an adult size to the pattern so the “adult” and the baby can have a cat on the head.

For the baby/toddler hat, you can use any worsted weight wool for this project. The adult hat uses Chunky weight yarn.
The Baby size is easily made with one ball of yarn. The Toddler may need a few yards of a 2nd ball or you can use contrasting yarn and make the cat’s legs/paws a different color.

This hat is easy to make, but you should know how to do the following techniques:
Provisional CO
Kitchener Stitch
knit in the round
embroider to knitting
3 needle BO

Therefore I would suggest this pattern for an advance beginner.

This hat has a one piece seamless look which I like. However, if you perfer not to work the Provisional CO and Kitchener technique, you can CO normally and sew the seam closed.