Instructions
Click on your witch's cauldron. Click "Make Regent" and then click "Dragon Scales." Click "Make Regent" again, but this time, click "Mystic Dust." Without these regents, you won't be able to cast the necessary spell.
Stop mixing regents when you have the right amount of each ingredient. You'll need one dragon scale and three portions of mystic dust. Click the "Inventory" button to see how much of the regents you've made.
Click on your Sim and click "Cast Spell," then click "Appello Cattus Amicus" to make a cat appear out of thin air. A message will appear, asking what you'd like to name your cat. Type the name and press "Enter." If you don't give the cat a name, it will keep its default name.
Teach your witch's familiar tricks, and train it just like any other Sims pet. If you want to take your cat with you to another lot, choose the cat as a companion when you choose a destination.
Click "Dismiss Spectral Cat" to dismiss your cat. Cast the summoning spell again, and it will always bring back the same cat. Your cat can also dismiss itself if you leave a lot without it or if its comfort meter is too low.