Composite Effects' Night King mask is the most recent addition to their Game of Thrones White Walker collection. Previously we saw one of the Night King's long-haired, extra-wrinkly cohorts. Both are designed to produce CFX's trademark "second skin" effect, a technique for crafting silicone into masks the company says are comfortable, durable, and lightweight, in addition to being hyper-realistic, screen-accurate replicas.
CFX creates its White Walker masks with official permission and license from
The Night King HBO's Game of Thrones, which might help them turn out the extensive detailing you see before you. Icy blue striated flesh. A smooth segue into the King's crown of ice. An expression that says, "You know nothing, Jon Snow. But you're about to find out."
Note: In this case, you do not have to go through training with the Faceless Men, and then kill the Night King in order to wear his face. You do, however, have to have a head between 21-1/4" and 23-1/2" in circumference, and many hundreds of dollars to spend on your cosplay and Halloween costumes.
PS: To all of you Game of Thrones prognosticators, I see your Bran-is-the-Night-King theory, and raise you one The-Night-King-Is-a-Crazy-Cat-Lady theory.