I am the only organ that named myself

Question: I am the only organ that named myself.What am I?

Question: Where do all the letters sleep?

Question: Tear one off and scratch my head. What once was red is black instead. What am I?

Question: What tastes better than it smells?

Question: What goes in the water black and comes out red?

Question: What loses its head in the morning and gets it back at night?