Related Clues:

• Greets the villain
• Scary sounds
• Makes like a snake
• Catcalls
• Expresses disapproval
• Derisive crowd emanations
• Disapproving sounds
• Shows disapproval
• Ghost sounds
• Sounds from angry fans
• Reactions to dirty tricks
• Angry cat sounds
• Radiator output
• Leak indicators, perhaps
• Disapproval from the bleachers