Ran across a whole section on this website of creepy things kids have said. Some are about little kids seeing people who aren't there. Others are kids just saying bizarre or creepy shit.
I have a creepy story about little kids myself. My grandma died when my mom was eleven. My cousin's daughter, who was three at the time, was over at my parent's house when I still lived there. My mom had a picture of my grandma in the hallway, and cousin's daughter points at it and says, "She visits me at night." Cousin said daughter would carry on conversations in her bedroom at night. She was an only child at the time, and they lived on a trailer that had one time been my grandparent's property (my grandpa split up the land between my mom and her siblings).
What bizarre or creepy stuff have you heard kids say?