Why not

Who?
"Why Not" is a person that emails some participants. Originally it was thought that "why not" was Jack but that doesn't appear to be the case.

Important Stuff to Know
This person corresponds on rare occasions but has an interesting e-mail "andthenitwaseleventhirtyeight".

Oct 10th emails: It has been  heavily inferring/ directly claiming on that it kills for fun.

It was Squirrel all along.