Just to be clear. I want a pattern for the stripes, not the whole animal.

I found a pattern for a crocheted bag in a zebra print...it has a chart on page 3...as knitting sts are wider than they are long and crochet sts are square, the print of the pattern would come out slightly wider than in the picture but it should still work. You can find it here:
http://www.kreinik.com/kshop/product.php?productid=122&cat=33&page=4
just scroll down and click on Click Here To Download