Aasimar are addressed in Blood of Angels. "Women that carry an aasimar child report easy pregnancies and deliveries..." There's an entire page of info on Childhood, another on Adolescence, etc. They don't come out and say it explicitly but there's no sign of any time disparity; they are described as maturing to age 5-6 like other human kids and having some issues during puberty with their peer group. BoA says, "An aasimar might spend a good portion of her childhood thinking of herself as human." This is odd as the Advanced Race Guide indicates that the adult age of an aasimar is 60, which would seem to indicate there's some kind of slowdown between birth and there... Same situation for oreads etc.
Bastards of Golarion has nothing to say about this for the other races, it's more of a crunch book really.
I think this falls into the general category of "poorly thought out things in the D&D cosmology," which are manifold. Just like the high intelligence of many aberrations, it's an interesting note trotted out every once in a while as a plot point and then conveniently forgotten 99% of the time.
So your playbook:
- Decide if you care - it's a magical world and these are magical crossbreeds, there doesn't have to be one answer and you can be as inconsistent as you want
- Decide if you just want to say "they mature at the same rate as anyone else" and ignore the adult age listed in the books
- Decide if you want to let players decide based on their own concept of their PC's background
Verdict:
This race is too strong, and includes one ability that, even on its own, is too much to grant to a race.
Explanation:
I'm making a breakdown using this guide for balancing new 5e races. It suggests that on average, a race is about 6 points worth of options. Most of the suggested abilities for your race are listed there, and counting them up, you end up with around 9 points. That means they're on the "very strong side" of races (beating out the Mountain Dwarf, which is currently the most powerful race), and could do with some fewer options. Especially considering I am not counting extra points for flexibility with the skills and +1 ability point.
However, that's ignoring one thing in your race which is incredibly powerful, way beyond anything another race gets (and pretty much forces the race down a single path) and that's the ability to cast the innate spells at your highest spell slot level.
This means that your race is able to cast 3 extra spells at their highest level spell slot every short rest, which is incredibly powerful. No other race has a leveled spell that's available every short rest. No class besides the Warlock even has that, and the Warlock only reaches 3 spell slots per short rest when they hit level 11.
Additionally, as they grow in level, they will ultimately be able to cast 4 9th spells per day, while any other character in the game only gets 1. (And the same applies at lower levels). Since all 3 spells you picked for them to get benefit from being cast at higher level, this is incredibly powerful; way beyond anything what other races grant. It also pretty much forces you down a spell-casting path, as you'll be missing out arguably the most powerful racial trait in the game.
Also, I'm not counting any point deduction for the vulnerability to Radiant damage. The number of creatures in the book that deal Radiant damage is next to none, so that trait isn't to come up very often.
Full breakdown of points
- Ability scores: 3 points (not increasing it for flexibility)
- Darkvision: 0.5 points
- Necrolyte magic: 1.5 points (ignoring the part about the spell slots scaling)
- Necrolyte training: 1 point
- Necrotic skills: 1 point (ignoring the flexibility, again)
- Fetid Attack: 1 point
- Radiant Weakness: I'm ignoring this because it comes up almost never and races usually don't have Weaknesses
- Languages: 1 point for 2 extra languages
- Everything else: 0 points; those are baseline
Suggestions
Definitely drop the scaling spell slots on the spell-casting. I don't think you'll be able to balance that. You should cut down on the superfluous features a bit; I'd suggest dropping the bonus skills, the unarmed attack and maybe one of the languages and/or the Darkvision. Dropping all of those would bring you to 6 points, which is balanced with other races.
Maybe even replace the two languages with "one language of choice". That still gives them a bit of that human flexibility (along with the +1 ability) that comes being based on them, while not making them too strong compared to other races.
I'd also drop the Radiant vulnerability. Not even most genuine Undead have that; it's unlikely to come up, and the one time during a campaign it comes up, it might well end up killing your character (or just being forgotten because it's never come up before.)
Best Answer
Only one of those is an official source
The listing from DnDBeyond is the only one that is officially supported. The others are fan sites or wiki that don't have official status. This answer has a complete (as of most recent edit) list of available official sources.
DNDBeyond is referencing the Elemental Evil Player's Companion where the Aarakocra was officially released in 2015. Therefore the correct answer is:
The tribality link is a homebrew race by Rich Howard created before the official version was released.
Similarly the grpg.wikidot version was last edited in 2011 before the official version was released. In fact the race is actually compatible with D&D 3.5e not 5e so isn't relevant material anyway. It doesn't have an author credit but is a public wiki and can be edited.