Board Thread:General Discussion/@comment-12265996-20141202030018/@comment-25094659-20141202233835

Icehard712 wrote: I'd support possibility 1; 2, 3, and 5 seem rather unlikely; and future Dipper, well, Disney XD did reference it in a promo for "Society of the Blind Eye."

Personally, I'm leaning most toward Stan (i.e., the Grunkle). Consider the fact that he didn't know about the invisible ink.