Clobbering Ankylosaur

Clobbering Ankylosaur doesn't untap during
your untap step.
{g}, {t}: Ankylosaur fights target creature. If that creature doesn't die when this ability resolves, prevent all damage that would be dealt to and dealt by that creature this turn instead.
At end of turn, if you didn't attack with a creature this turn, you may pay {w}. If
you do, untap Ankylosaur.