Black-crowned night-heron 
(Vạc, Nycticorax nycticorax), or black-capped night-heron, commonly shortened to just night-heron

The black-crowned night heron (Nycticorax nycticorax) is a medium-sized heron found throughout a large part of the world, including parts of Europe, Asia, and North and South America.

The name Nycticorax means "night raven" originating from the Ancient Greek: nuktos "night" and korax, "raven". 
the night herons of the genera Nyctanassa and Gorsachius were formerly placed in Nycticorax.