Familiar

Familiars are magical creatures that act as companions for witches and spellcasters in The Sims 2: Apartment Life (when The Sims 2: Pets is also installed) and The Sims 4: Realm of Magic. Witches in The Sims 3: Supernatural get a moodlet that boosts spellcasting if they own a cat or a small pet, but these pets are completely normal otherwise.

The Sims 2: Apartment Life
If players also have Pets installed, witches can summon their own cat familiar called a spectral cat.

The Sims 4: Realm of Magic
In Realm of Magic, spellcasters can acquire magical familiars that can aid in spell casting. Familiar types that have been confirmed so far are dragons, phoenixes, ravens, owls, frogs, bats, voodoo dolls, flaming skulls and non-anthropomorphic fairies. If players own Cats &amp; Dogs, they can make their pets familiars as well.