Mozambique.
Mozambique is the only National flag that has a modern firearm as part of the flag design. The gun is an AK47.
The country of Mozambique has a AK47 with a bayonet attached to the barrel. Here is a reference link http://en.wikipedia.org/wiki/Flag_of_Mozambique
I believe you may mean "graven" image. A graven image would refer to a carved or crafted idol, an object that a person would bow down and worship. Where a very few people might worship the flag, the majority of people would not. I don't think many people would refer to the flag of any nation as a graven image.
See related links for an image of the Greek flag.
you can see an image of the flag of colombia at google or yahoo.com...
Yes, most nation states have a national flag.
Such a flag is called a national flag.
Go to Google Image search and type "Greek flag" See related link.
Both Cyprus and Kosovo depict the outline of their nation on their flag.
Manibota's flag has an image of a bison on it.
The Newbrunswick flag has an image of a boat on it.