Cow, is Chicken's 7-year-old cow sister, with a weight stated as 600 pounds. She is usually viewed as exceedingly infantile and stupid, and is quickly prone to emotional outbursts, but she occasionally displays uncanny talents. Though she looks up to her older brother, Chicken, thinking that he is cool and usually lovingly addresses him as "Big Brother", it has been shown many times that she would not hesitate to use blackmail to get Chicken to do what she wants, proving that she has all of the mischief and wit of a younger sister used to getting her way in all things, due to her status as the baby of the family.
Despite this, however, it has also been proven that Cow has a heart of pure gold, and would always try to get the other characters to do the right thing. Another important point that should be noted is that she has always been there to get the impulsive and headstrong Chicken out of whatever trouble he got himself into, whether resorting to her alter ego or not, proving that she really does love him very much. No fucking giving. [Source: wikia]