This weakaura will automatically put a bar above your head when you 'Polymorph' sheep any target or player.
This bar is an indicator of how much time your 'Polymorph' has left before breaking. However, remember if your 'Polymorph' is cancelled by a special ability from the enemy, and enemy's teammates, or your own damage (of course) the bar disappears when the 'Polymorph' is broken.
The text, color, size, and more can easily be adjusted within the weakauras option panel.