Deadly Eyes (1982) 

Corn grain contaminated with steroids produces large rats the size of small dogs who begin feeding on the residents of Toronto. Paul, a college basketball coach, teams up with Kelly, a local health inspector, to uncover the source of the mysterious rat attacks and they eventually try to prevent the opening of a new subway line as well as find the mutant rats nest quickly, or there will be a huge massacre of the entire city! - IMDb

 

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