Hmm, maybe not necessarily unreliable narration, but more towards myth. All the Crayon we've seen have involved the gods in flashback to some extent. Then there the order of the scribble and Ochul...
The Crayon may simply be the Legends (which by nature are unreliable and may differ in detail from the truth) of the OotSverse being told.
EDIT: Legends or Legends in the making.