The Blue Calf is the offspring of a Bull and Blue Cow. Its parent, the Blue Cow was released on the November 05, 2010 as part of the Megamind Promotion Event. When you harvest milk from your Dairy Farm (with 1 Bull and at least 1 Blue Cow inside) there is a chance that a Blue Calf will be born. When you harvest from your Cow Pasture with at least 1 Blue Cow there is a chance that a Blue Calf will be born.