The average 5 year old weighs 50 to 70 pounds and is an average of 39 inches tall. That's eyeball to my groin and a little hefty to pick up and throw very far. I guess you could gouge their eyes out to incapacitate them and come back later and snap their necks. A 5 year old's body is too soft and 50 pounds is too heavy to use as a club. There'd be a lot of blood on the floor so it would be slippery. You could bare knuckle it for a while.

Of course it depends on the 5 year old. If the kid is big for his age, one day away from this 6th birthday, has been working out, has multiple rapes and murders to his credit already, is a sociopathic leader of a 50 member violent street gang, is high on meth, determined and thinks I'm ugly...well there you are. It might only take one!!