Why are there pixies, etc. on the First but not the Source?

[Zohar_Lahar]

Where have all the fae gone? Did they evolve into elementals? Spriggans? Harvested to make SCH soul crystals?

[Astrid_Stormborn]

You could say that the pixies are the 1st Shard's answer to our Sylphs. Creatures of not quite human mindset who love pranks.

[Anhra]

If i had to make a guess, they either:

1: Do exist, but in a area we don't have access to.
Or
2: Only exist because of a specific Event which only took place on the first.

From what i know and remember (correct me if i am wrong), the Pixies settled in on Il Mheg after the fall of the Voerburt Kingdom and turned its remaining citizens that didn't left into those humanoid grass bushes we see all over the place.

Pixies also seem to be born from the souls of dead children, and unless there is some sort of sidequest i missed out that states othetwise, there is no further information on this to prove Theory #2.

[ItMe]

But the Sahagin and Ondo are clearly the same thing.
As are the Kobold and the Mord.

The Pixies and Sylph aren't remotely alike, and I don't just mean visually. The Sylph are their own race where as the Pixies are dead kids.

[DPZ2]

Accept the fact that the peoples, lands and lore of the First are not those of the Source.

If you must, consider the connection between the two as a set of parallel, non-synchronous universes.

[Iscah]

Accept the fact that the peoples, lands and lore of the First are not those of the Source.

If you must, consider the connection between the two as a set of parallel, non-synchronous universes.

Yes and no.

The same races exist even if their cultures have diverged, and the overall rules of how the world works are the same. The laws of physics (and the more magical sciences like aetherology) apply the same way in both.

If it is a "natural phenomenon" that the souls of children spontaneously turn into pixies, we should expect to see this happen in the Source as well, but we do not. Therefore either it is happening and we don't see it, or it is not happening.

If it's happening, where are the Source's pixies hiding?

If it's not happening, what caused it to happen in the First?

[ItMe]

If it's not happening, what caused it to happen in the First?

Necromancer confirmed.

[Rosenstrauch]

This is all spitballing here, so don't take what I have to say too seriously.

One possibility is that the Pixies underwent a radical transformation on the Source as a result of one or more calamities. It's possible that one or more calamities resulted in Source Pixie souls being too dense to remain as Pixies, and they took on new forms instead. Another is that Pixies themselves are the result of an emergent species. Perhaps every Reflection has Pixies and the Source never did, because of some quirk involving the Reflections' connection to the Aetherial Sea.

Maybe the Pixies on the Source are just hiding. Maybe the WoL is a Pixie in disguise.

[Lumivyory]

While there are some beast tribes that exist only on the First, there are also tribes that exist only on the Source.

Other than the Pixies, the Source also doesn't have Nu Mou, nor do they have Amaro (which technically are their own tribe with those that regained intelligence).
On the other hand the First doesn't have Sylphs, Namazu, Ananta, Kojin, Vath, Vanu Vanu and even Moogles. Some of these I'm guessing existed before the Flood but there is no way to know which ones. Maybe they even had other beast tribes that don't exist in on the Source but those were also wiped by the Flood.

So Pixies are probably their own thing that only appeared on the First due to whatever made them come to be, same with Nu Mou and Amaro.

[Enkidoh]

On the other hand the First doesn't have Sylphs, Namazu, Ananta, Kojin, Vath, Vanu Vanu and even Moogles.

Moogles do exist on the First as well - they have blue poms and are seen even running a version of the Moogle Delivery Service (presumedly G'raha established it there based on the Source's one, but it still leads to questions as to how that can connect with the Moogle Delivery Service on the Source - presumedly it's similar to how retainer services are handled by Feo Ul, but that's a long shot).

Ananta and their lamia cousins not existing on the First makes sense though, given those were synthetic creations of the Allagan Empire same with the giants/gigas and so never had a counterpart form on the First when the Sundering happened (although it's possible some might have hitched a ride to the First via the Crystal Tower like the gremlins did). But as you said, a lot of beast races on the Source not being seen to have counterparts on the First can be just chalked up to being rendered extinct by the Flood of Light.