Answer:
With three leaves, I am just a plant. Add another leaf and everyone will want me for good luck. What am I?
I am alive without breath and cold as death. I am never thirsty but always drinking. What am I?
When I live I cry if you don't kill me I'll die.
You use a knife to slice my head and weep beside me when I am dead.
I am a key that is playful. What am I?
What made Cyclops quit teaching?