Cricut.com has it for $69.00
http://www.cricut.com/shop/#0/1/969/3/Cricut/Cricut Create a Critter Cartridge

Here is one for $44.99

http://www.ohmycrafts.com/search.aspx?find=create++critter

eBay
http://shop.ebay.com/i.html?_nkw=create+a+critter&_armrs=1&_from=&_ipg=

This one is $39.99

https://www.scrapbookpal.com/Index.asp?rid=029

Just type Cricut Cartridge Create a Critter into your browser and see what comes up, then check them out.

Good Luck..