Possible Clues:

• Runaway
• Unchecked
• Growing or spreading uncontrollably
• Unrestrained, flourishing excessively
• Unrestrained, a politician during tirade
• Showing unrestrained growth
• Flourishing excessively as disease may be
• It will make the sheep to be out of breath to have him standing on his hind legs
• Unrestrained, as animal may be in heraldry
• Violent male animal to huff and puff