Cow and Chicken - Season 4 Episode 2 Black Sheep of the Family
Overview: Cow and Chicken get a visit from their cousin, Black Sheep (who really is in both terms). While Mom and Dad run away, Cow and Chicken try to make Black Sheep feel at home, but when he compliments Flem and Earl in scientific terms, they assume that Black Sheep is a dangerous criminal. Cow tries to help Black Sheep, who everyone changes their minds about, after he saves a woman's life from a heart attack.