Related Clues:

• 'Attack, Fido!'
• ''Get him, Rex!''
• Attack order
• Order to a guard dog
• 'Not a typo' indicator
• 'Attack, Spike!'
• [as submitted]
• "Attack," to Rover
• [it was wrong before I quoted it]
• Start of an order to an attack dog
• Attack signal
• "Attack!"
• Word to an attack dog
• [thus]
• Attack, to a dog