With the Biotech DLC. It is possible to edit your custom race and add this trait via gene edit. Just found out that this trait lowers the value of your colonist with this race by a lot. If you play the run by wealth scaling, this will make raider a lot easier. Also, this gene gives +2 Metaborism which make your race eat less food.
To counter its negative. Add the Kind instinct gene. It forced all the pawn in the race to have kind trait. Kind trait pawn will never judge people by their look, which negate all the negative of the staggering ugly. Also, kind pawn will never insult or start social fight first. It's made a good combo with Bloodlust trait and alcohol dependency if you can provide them booze. They will never have Abrasive or Psychopath trait though. They also give kind word for minor mood boost as well.
Still, this is only work if you plan to make a colony with only 1 custom race. Other people still find staggering ugly pawn a good punching face and will insult them on sight. They could have slave from other race though (other DLC, can't remember which) because slave never insult your pawn from my experience.External link →