in development. Bachchan was reported to be playing the father of Mohanlal's character, and Prakash Raj and Manju Warrier were in substantial roles. The film is based on the legends of the "Odiyan" clan—mythical black magicians with the ability to shapeshift by using a trick called odi vidya. The mythical clan, which supposedly Inhabited the Malabar region of North Kerala, were said to terrorise people to death by appearing in animal forms called odi veykkuka at night. This story was based on folk tales of Odiyan; Harikrishnan did not undertake any additional research. On 26 March 2017, Mohanlal confirmed the project officially via social media. He wrote that Antony Perumbavoor would produce the film through Aashirvad Cinemas, and that Sabu Cyril—who was later replaced by Prashanth Madhav—and Shaji Kumar would serve as production designer and cinematographer. Warrier would play the female lead role—though he did not mention Bachchan, Raj or the 3D format. According to Menon, Odiyan is a "rustic thriller" and the story is based on the tribes of Odiyans and their myth. Odiyans are said to have been the first "quotation gangs" (hired criminals) in Kerala, who went disguised as animals during night hours to attack their enemies. Menon described the film as a magical realism thriller. Both Menon and Harikrishnan originate from Palakkad (Malabar) and grew up hearing the legends of Odiyans during their childhood. It was Harikrishsnan's long-time dream to write a story on Odiyans. The film is also set in rural Palakkad. Menon and Harikrishnan initially planned a children's film titled Randu Vaanavillukal, which was set in the drylands of Tamil Nadu. Before filming, however, the Tamil Nadu flood happened, turning the film location green and lush, making it unsuitable for the film and their plans to shift the location was unsuccessful. The two met again for a follow-up discussion. Odiyan originated from a conversation between Menon and Harikrishnan. Menon liked a one-line story narrated by Harikrishnan, who later wrote a single scene for Odiyan, which he intended as the introduction of the title character. He showed it to Menon, who sent it to Mohanlal and the project got underway. The scene remains in the film's final cut. Earlier, writer-director A. K. Lohithadas had proceeded with a story based on an Odiyan with Mohanlal in the lead role, but it was not made into a film. Director Lal Jose also contemplated making such a film,