Brawn, Pride of the Mountains

Haste, First Strike, Stubborn {w}{r}( if this creature is tapped you may pay its stubborn cost during the assign blockers step to untap it. It must be assigned to block if possible.
When Brawn, Pride of the Mountains enters the battlefield, untap all plains and mountains.
All of your lands have {t} to produce {r} in addition to their other abilities.