Easiest solution, each time a chicken is eaten play a "chicken death" sound and make some feathers fly around the point the chicken was, kind of like when you slapped one in DK. Or you can transform for a second the chicken on a roasted chicken with some small magic effect before its eaten, since they are magical right? junk food to the max.
Animations could be more inmersing, but think each creature has different heigth and some of them doesnt even have hands, above solutions could e more efficient in my opinion.