Well! We could look to Lovecraftian mythos for a new abberation-heritage design? I think it's safe to say Cthulhu and the Illithid he spawned are clearly off-limits to avoid any kind of imminent lawsuit from WotC.
The other big ones from the "Great Old Ones" range are Hastur and Yig.
Yig is the basis of Dendar the Night Serpent and the Yuan-Ti really cover a ton of the identity, there. Twisted snake-people and all.
Which leaves us with Hastur, the Yellow Sign, the King in Yellow....
Who is, of course, associated with the Worm that Walks.
It's almost like WotC mined Lovecraftian myth almost directly to try and make their Aberration stuff!
So what if we took a step just to the left and touched, instead, on the Oghru Jahad, of Hellboy, and their minions, the Ogdru Hem, instead?
Sammael, the Hound of Resurrection, would be a very interesting basis for a player heritage. Four eyes, tentacle-hair, concentric ring symbols on the body hearkening to -something- else. Three tongues on the end of a stalk that can extend outward... Not to mention the bony plates and brain-wrinkle patterns on specific parts of the body.
There's a -lot- of stimulating visuals you could mine from that interpretation.
Alternatively there's Cipactlhem for something very simple: Extra Mouths.
We definitely don't have any player character options with secondary mouths, and the gibbering mouther is a core aberration... Just thoughts!