There are plenty of monsters in director Bong Joon-ho’s movies, but the monster and the film that would firmly establish Bong as a creative force of nature and future success in Hollywood is “The Host,” the wild 2006 genre mash-up.

A monster (the ‘Gwoemulä) is birthed through pollution in the Han River and grows to massive size. Going on a killing rampage along the shoreline, the creature grabs Hyun-seo (Go Ah-sung) and takes her back to its lair. Her dad Park Gang-du (Kahn Gang-du), along with his father Hie-bong (Hie-bong Byeon), his unemployed alcoholic brother Nam-il (Hae-il Park), and his Olympic archer sister Nam-joo (Du-na Bae), swear revenge on the creature and will try anything in their attempts to save little Hyun Seo.

Written (in part) and directed by Bong Joon-ho, The Host (괴물 or Gwoemul aka Monster) is a South Korean monster film. The movie became one of South Korean’s highest grossing films of all time (with a relatively low budget) and received critical acclaim around the world.

The movie is a nice mix of genres: monsters, comedy, thriller, and underlying political commentary. The special effects are surprisingly good considering the relatively low budget the movie had (just over US$10 million). The creature was designed by Chin Wei-chen, the modeling was done by New Zealand-based Weta Workshop and the animatronics were by John Cox’s creature Workshop.

The monster was designed with some specific parameters in mind. According to an interview with Bong Joon-ho, the inspiration for the monster came from a local article about a deformed fish with an S-shaped spine caught in the Han River. Bong Joon-ho wanted it to look like an actual mutated fish-like creature, rather than have a more fantastical design.

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While Gwoemul had a segmented jaw and multiple other mandibles rowed with dreadfully sharp teeth, it appeared to only be able to ingest food whole.

Gwoemul was a large amphibious predator mutated from an unknown organism (though it has been mentioned by some to be a Tadpole, but this has not been confirmed) by various pollutants in the Han River. It was an extremely aggressive and dangerous creature that would often hunt humans near the river, bringing them back to its lair in the sewers.

Non-alien Creatures Wiki