Related Clues:

• Crevice or crevasse
• Greedy gullet
• Paw's spouse
• 'I saw the opening __ of hell': 'Moby-Dick'
• "I saw the opening __ of hell": "Moby-Dick"
• Opening piece of music has magnificence
• Big rift
• The jaws of an animal
• Big difference
• Critter's stomach
• Gap in sandwich as mentioned
• Animal's pie hole
• Mouth (animal's)
• Charles and Mike in Split
• The Grand Canyon, notably