They said that child was held against his will and a cult leader performed dark magic to stunt his growth.

I guess they were trying to explain the monsters origins yet it doesn't seem to fit the description of it. Its a monster not a spirit that inhabits corn fields.

I guess you could say the sickness the kids got fits in with II, but still the guy was drowned in a well not buried in a corn field or how he got the ability to move around like a tremor