The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

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

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?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

Solve the following series:
AZ, GT, MN, __, YB