Related Clues:

• It's a fault's fault
• The first X of X-X-X
• 2 or 3, maybe, on the Richter scale
• Shaking
• Mannerism
• Certain X
• Behavioral quirk
• Quirk
• Twitch
• Quake
• Facial spasm
• Part of X-X-X
• Earthquake
• Part of OOO
• Facial movement