Bevendre

Pegasi who opt to choose to become cowponies indefinitely often do so because of a sense of dissociation with their pegasus heritage and a distaste for flying.  Others, in the cowpony blog at least, only do it temporarily for a sense of comfort, power, and pleasure.  Cowponies do have magic, so it is still possible for them to manipulate weather albeit much more limitedly than unicorns and especially pegasi.