Answer:
I have green hair a round red head and a long thin white beard.
You heard me before and then again. Afterward I die until you call me again.
I can be thin but not fat; in your body but never on your placemat. I'm always better when I'm fresh but you'll never see me in the flesh.
I can be repeated but rarely in the same way. I can't be changed but can be rewritten. I can be passed down, but should not be forgotten. What am I?
An action done on mosquito bites
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.