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