The key of the powerful kick of a donkey is not only in the strength of its hind legs. It is in fact, using its whole body (including its long ears) when kicking the foot ball. If you add its passion of football, its enormous enthusiasm and its advanced technique, joined to a tireless and persistent (almost stubborn) attitude, you end by having an unbeatable killing machine, perfect to powerfully kick foot balls, score goals and beat any goalkeeper.
(Or a similar design)