I wear a colorful coat outside, but inside I am stark naked, and I wear my seeds on the outside of my skin. What am I?

I am born in the dark, raised in a cold box, and my entire life's purpose is to melt in someone's warm beverage.

I am an instrument that can open any door, yet I have no handle, key, or hinges.

I have a sharp tongue, but I never speak. I slice through heavy cloth and paper with ease, but I am afraid of rocks. What am I?

I wear a tuxedo all day, waddle like I'm late for an important meeting, and my best winter coat is completely waterproof. Who am I?

I have a thick spine and hundreds of pages, but I cannot read a single word. What am I?

I am an instrument that can make sound, but I have no strings, keys, or buttons. I have no tongue, yet I speak every language known to humanity. What am I?