cobra:  Cobra is a shortening of Portuguese cobra de capella, which came into English in India in the 17th century. This meant literally ‘snake with a hood’: cobra from Latin colubra ‘snake’ and capella (referring of course to the ‘hood’ it makes when agitated, by spreading out the skin at the side of its head) from Vulgar Latin *cappellus ‘little cape’, from late Latin cappa ‘hood’. => cap, cape, chapel, chaperon
1802, short for cobra capello (1670s), from Portuguese cobra de capello "serpent (of the hood)," from Latin colubra "a snake, female serpent" (source of French couleuvre "adder"), which is of uncertain origin. So called for the expandable loose skin about its neck. The word came to English via Portuguese colonies in India, where the native name is nag (see naga).