So... I figured out the exact spots for the spawns 👍 The primary spot is just behind the red obelisk on the thin little strip of land near the southern island. (I almost always see one spawn there) I also find them frequently spawning around the “back spike” of the red obelisk. You will almost always find a quetz around these two places. (At least on mobile) If you want a high level, just kill the one that spawns at these two places and a new one will always respawn back at those two places. This technique worked for me.
Qetals are ALIENS! creatures. They are very rare, but the main thing is that they never go down, unless you made one unconces. They even spawn on the air, but how do they grow up and be not hungry, thirsty, but healthy. If they can survive up there they arn't normal creatures. They have to be a different complex organisms. UP for more documentaries.