The farmer's name is Hunt Hansen,a nod to Gunnar Hansen who played Leatherface in The Texas Chainsaw Massacre(1974)
The children of Everett Blackheart became feral after being trapped in the hole for so long, which resulted after so little human interaction aside from Hunt Hansen's. Feral children are absolutely real, with the earliest known case dating back to 750BC with the founding of Rome being named after the eldest of the feral twins, Romulus and Remus. Feral children are still found to this day, whether they are just left in the woods, or raised by animals.
This film is heavily inspired by the Texas Chainsaw Massacre franchise.