60 Seconds! Reatomized

This achievement requires you to basically aim for it. As you progress through the game, you will eventually find a cat named Sharikov.

Eventually you will get these options. Follow what is suggested below:
"Sharikov was playing and we saw a wire should we follow it?" "YES"
Next day: "Should we talk to the FBI agents "X/No"

"We found an address on his collar should we go?" "NO!"

"Sharikov has been leaving through a small hole should we follow him?" "NO"

After you do these continue to play, and you will get multiple cats that appear in your shelter. RUN OUT OF SOUP, and they will kick you out of your shelter.
If you have enough soup you will get the other "Cat Overlord" achievement

This is one of the endings and is not too hard. You want to get the event in which you get the cat inside of your house and once that cat is inside do not go to the adress on the cats collar and basically ypu just want to stay alive long enough til the cat brings in other cats, you want to make sure you do not have a surplus of food and you will eventually run dry of food getting this ending.