Amphibians and reptiles

An English reader who meets die Kreuzotter in a German field guide sees an otter in it, and there is none. Die Otter, feminine, is a viper, and at the end of a compound it names a venomous snake: die Kreuzotter is the adder, the one venomous snake of northern Germany. The furry animal that fishes in rivers is der Otter, masculine, and that is the real cousin of the English word. So the article, and in a compound the context, separates a mammal from a snake that bites. The neighbouring word pulls the other way. Die Natter is an old relative of « adder », yet in a Central European field guide it names the harmless snakes, such as die Ringelnatter, the grass snake. Read -otter as a warning and -natter as the all-clear, and the snake pages sort themselves.