Pintail or northern pintail 
(Vịt mốc, Anas acuta) 

The pintail or northern pintail (Anas acuta) is a duck species with wide geographic distribution that breeds in the northern areas of Europe and across the Palearctic and North America.

anser: Latin anser goose;
anas, anatis: Latin duck.
The epithet acuta comes from the verb acuere meaning "to sharpen" which refers to the pointed tail of the male in breeding plumage.