Related Clues:

• Sound from pen with love for writing
• Sow's sound
• ''Old MacDonald'' sound
• Sound from Wilbur or Babe
• Sound of animal from an empty pen?
• Piggy parlance
• "Sooey!" reply
• Hog heaven sound?
• Disdainful sound
• Remark from a sty
• Hog's grunt
• Babe's sound?
• Pig's grunt
• Sound in a 20 Across
• Stallion's huffy sound