how to create and add custom inventory to entity that i would pickup every items, that it finds automaticly like player, and would have like 9 slots

 

and would drop all that it has in inventory when dies

Your question smacks of the open-ended type of question like, "I don't have any idea how to write a mod or get started, so take my requirements and make me a mod that does it."

Reminder:

We don't write mod code for you here. Find a tutorial and try and find a similar thing in Minecraft code.

i know that i just asked for proper tutorial for that

http://www.minecraftforum.net/forums/mapping-and-modding/mapping-and-modding-tutorials/1571597-1-7-2-1-6-4-custom-inventories-in-items-and

 

May not be for "other entities" however it shows you how you would add an "inventory" I would then also suggest looking at zombies in vanilla minecraft but I ran through it and didn't find any idea how they hold armor and can pick up 1 item (shovel, sword, dropped item)

 

So i'm not sure where can find a tutorial for non player entities having inventories and dropping them on death. But I know the posted one works for custom player inventories and hopefully you can get something out of that to get an understanding and maybe you can then play around with it?