Hello, I'm a new member. I knit and crochet.
There is a free crochet pattern on Lion Brand yarn's website
Trusty Old Dobbin Hobby Horse
I crocheted one for my daughter in pink homespun, with a purple mane in 4 ply yarn. It came out cute and my kids love it. You could probably convert the pattern for the head part and ears to knitting, but the mane would have to be changed up a bit.
My husband also used a staple gun to help keep the head on in addition to drilling a hole through the stick and sewing through it.
Hope this helps.