I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

What you cannot hold but it is yours?

What has many keys but can’t open a single lock?

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

Give it food and it will live; give it water and it will die.

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?