This is a monster from Toho Animation's 2016 CGI anime Gantz:0, based on the Japanese manga Gantz. If you haven't seen this movie yet, it is highly recommended as it features excellent CGI and some of the most original and fantastic monster designs. The film doesn't give much backstory on the monsters or were they come from, but it is a visual smorgasbord for monster lovers.
The colossal head is one of the first monsters the film's protagonists encounter. It is literally a gigantic, disembodied human head that rolls about crushing everything in it's path. The head displays a full variety of expressions, but seems to have very little intelligence. The colossal head has a great deal of brute force as it rolls effortlessly through walls and over cars. It crushes people as well as fellow monsters until it is dispatched by the heroes.
Gantz 1

the colossal head from Gantz:0

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