I don't know what kind of snake that is, but the head shape you describe sounds like a viper. Can you see a real definition from the head and body? It doesn't flow as one? If that is the case it could be a viper. Since you don't know stay away from it.
A Hognose snake
A brown snake or a young tadpole.
the Asian blind snake has indentations on head instead of eyes has rosy and white scales is that the snake you were wiki ing for?
Lots of snakes are brown and black. You'd need to be more specific about the patterning, size, head shape, and location you spotted the snake to get a good answer.
bald eagle
The coral snake as well as a number of other elapids, such as the mamba, have an oval-shaped head and round pupils.
Non poisnous snakes
eastern brown snake, western brown snake also known as gwardar, mainland tiger snake, inland taipan, coastal taipan, mulga snake also known as king brown snake, low lands copper head, small-eyed snake, common death adder, and last red-bellied black snake. All of these are poisonous, some may cause death.
it is a pyaton
It is possible, but extremely rare. If a snake has two heads, that means four eyes instead of two. I don't know if a snake can have more than two eyes on one head, but yes, having more than two eyes is possible for a snake.
The description matches that of a garter snake. Garter snakes are known for their black, brown, and sometimes green stripes running along their bodies from head to tail. They are common in many regions and are non-venomous.
No. If you cut a snake's head off it will die.