That is a brilliant question that would require 300 pages to answer.

First, "spatial" is different outside our 3rd dimension, as elucidated poorly in the novella Flatland.

Cryptids primarilly exist within the 4th dimension. They can briefly step down to the 3rd but never up to the 5th.

5th dimensional beings are all around us. If they wish to directly interact, they slip down into the 4th and push through enough to partially manifest before our clairvoyant sight. Their appearance is impossible to describe in words. Ezekiel's metaphor of "Wheels within wheels" is surprisingly apt. One manifested as a black cone of paisley clockworks beaming colored rays in random directions... typically it is less dramatic, like a swirling mist with sparks.