In Chapter 13 of this great novel, Kenny, Joetta and Byron go for a swim. However, Kenny ignores the advice of Byron and Grandma Sands and wants to go to Collier's Landing, where he has been told that a boy drowned because the water there is so dangerous. Byron makes up a story of the Wool Pooh, whom he says is Winnie the Pooh's evil twin brother:
"What he does is hide underwater and snatch stupid kids down with him."
Clearly, Byron is creating a fictional monster out of the whirpool and the strong currents that there are in Collier's Landing. However, in spite of these threats, Kenny goes and starts paddling in the water by Collier's Landing. At first he tries to catch some fish, then as he makes a grab for a big turtle, he loses his footing and finds that he can't make his way back to shore. When he gets really scared, that is when Kenny sees the Wool Pooh, who is:
...big and grey with hard square-looking fingers. Where he should have had a face there was nothing but dark grey. Where he should have had eyes there was nothing but a darker colder-looking colour. He grabbed my leg and started pulling me down.
As he fights with the Wool Pooh, Kenny imagines that he sees an angel who looks like Joey who encourages him to fight for air. Then he realises that Byron is in the water with him, fighting the Wool Pooh for Kenny. Finally, Byron wins, and drags Kenny out of the water. Kenny then vomits up lots of water and food and Byron cries in relief.
Kenny felt as if he was going to die so the Wool Pooh was just a way of portraying death kinda like the grim reaper same as the church where the the four little girls died that was also a place where death was in the air which is why the Wool Pooh was there too.