The Disney movie, Beast, is a live-action retelling of the classic fairy tale, Beauty and the Beast. The film stars Emma Watson as Belle and Dan Stevens as the Beast. While many of the characters in the film are CGI creations, Stevens' Beast is primarily a costume with some CGI elements.
The costume was designed by Jacqueline Durran and made up of several different pieces. The headpiece was created separately from the body suit and took inspiration from real-life animals like lions, bears, and wolves. It also had to be able to accommodate Stevens' 6'3 frame.
While most of Beast is played by Stevens in costume, there are some key scenes where he is replaced by a CGI creation. These include the scene where Belle first meets Beast and the scene where they dance together in the ballroom. In both cases, animation was used to capture Stevens' performance so that it could be replicated by the CGI version of Beast.
Overall,Beastis a mix of CGI and costumes with some key scenes being entirely CG animated. This allows for a more realistic portrayal of Beast while still keeping him true to his animated roots.