Here is the full list of all 12 Karen: An Outrage Simulator achievements.
You have reached the ultimate form
Nobody's having a good time if you aren't
Rage at the restaurant
True serenity, through the misery of others
Go ballistic at the spa
Nobody tells you what to do
Erupt at the grocery store
Spoke with the manager, and destroyed him
Throw a tantrum at the Starcups
Lose your cool at the Con-Mart
Expiry dates are just suggestions
You are now Karen