Director Yi Zhenxing (right) and actor Jia Nailiang attends a press conference. [Photo provided to China Daily]

The Internet hit series Surprise continues to surprise.

The grassroots-themed serial has been watched 2 billion times on Youku.com, one of China's largest video-streaming sites, in the past two years.

Now, encouraged by its popularity, the crew behind the low-budget series has turned the program into a feature-length movie.

The film, which will open in mainland theaters on Dec 18, weaves the lead characters' adventures into myths featured in the ancient Chinese classic Journey to the West.

Chinese actor Bai Ke, who shot to stardom in Surprise, reprises his lead role, Wang Dachui, in the movie, but the human character is a low-class monster of the same name.

Once a local big brother leading a monster gang, the monster's peaceful life is disturbed when the four famed Journey characters, Buddhist monk Xuanzang and his powerful three disciplines, challenge his authority.

Similar to many Internet sensation-adapted movies, Surprise boasts a high-profile cast. The stars include Taiwan actor Bolin Chen and rising actress Yang Zishan, who is known for the fantasy blockbuster Miss Granny.

Yi Zhenxing, better known by his pseudonym Jiaoshou Yixiaoxing, has the director's job just as he did in the series.

The team behind the series, who have so far released two seasons and 33 episodes, will release the third season on Nov 3.