The Indian cobra,
Naja naja, shown here with its hood expanded, is often regarded as the
archetypal cobra
Cobra is a name of a snake. In English it is the common name for various venomous snakes. Most of those species are in the family Elapidae, and most of them can spread their neck ribs to form a flattened, widened hood.
The name "cobra" is short for cobra de capelo or cobra-de-capelo, which is Portuguese for "snake with hood", or "hood-snake".