Spirituality is rife in Oddworld's lore and I always felt as though the Shrykull was somekind of manifestation of the vengeful spirits of the Scrabs and Paramites. We know that Spirits have some kind of power and influence since they can also do things like open doors for Abe, or communicate with him through visions as we see in Abe's Exoddus.
I've spoken briefly to Lorne about Shrykull, though I was actually asking about other dualistic dieties so nothing interesting to learn about the Shrykull itself.
__________________
|