1) Asp 1) Bane of an off-key tenor 2) Communicator 3) Curtain-call critic 4) Disapproving one 5) He greets the villain 6) Loud, obnoxious fan 7) Many a snake 8) Noisy snake 9) Snake or cat, on occasion 10) Snake, at times 11) Snake, on occasion 12) What an angry snake becomes 
[n] - someone who communicates disapproval by hissing