3e and 4e made the Elan race Aberrant. But this example, is a human that was psionically modified by the Far Realm. So it looked like a normal human, rather than the more monstrous appearances that Aberrants often have.
Note, one of the Eberron dwarf cultures traffics with Aberrants. So, perhaps this culture could choose between being Humanoid or Aberrant.
I dont think all Aberrants are psionic, but some are.
Heh, I treat Aberrant as if the "real" Neutral Evil Fiend. More selfish than Devil but less self-destructive than Demon.
Creating a new Aberrant race that looks like a squick nightmare (tenticals, mouths, eyes, etcetera), as a player character is fine. Personally, I tend to associate this nightmare archetype with the sea anemone.
The design space of 1½ feats can do alot to forward a character concept: maybe focus on charm and frighten, while inducing nightmares and corrupting personalities, but also creating Difficult Terrain by warping the nearby reality. The terrain effects would be temporary but might become permanent if applied everyday for a year.
Of course, player characters can be any alignment, and even a Fiend might be non-Evil.