I occasionally wonder how birds are given their common names. In this instance, I suppose, 1 out of 3 isn't bad in the description department.
First - The crown of the Black-Crowned Night Heron isn't black. It's dark navy blue.
Second - For a bird that's described as a "night heron", it certainly appears in the daytime regularly, including in and around noon time.
So that leaves us with "heron". That part's right. A much smaller compatriot to the Great Blue Heron, it too enjoys the same prey such as fish, small crustaceans and the odd small muskrat. :)
So here are some photos of the "Black-Crowned Night Heron". And depending on its positioning & activity, it can change appearance quite dramatically.