Companions in your Baldur's Gate 3 party will react and have dialogue options about the choices you make on your adventure. These companions should feel like characters in their own right, even if you didn't create them, and they are the party members you are traveling. Pets, on the other hand, are lesser beasts that you control. There are different ways to add them to your service. For example, a character who is expert at handling animals could have trained a large spider, a cat, or even a small dog to join your party. You normally have to do everything you can to get these strengths, and having a certain level of skill helps too.
What is a familiar?
When a familiar joins you, it is a step below your companion. They usually don't have a direct opinion on the choices you make. They follow your orders without any dialogue or any contribution of their personality. You can creatively use a familiar to alter the surroundings. For example, if you need to pass guards, you can use your pet to attract them, and your main character can pass the time. Your pet does not need to be within a set distance. They can travel anywhere on the map without your character being nearby.
What types of pets are there?
You can meet various familiars while playing the game. Your skills and abilities come into play to determine which ones can accompany you on your adventure. For example, during the Panel from Hell live stream, the team at Larian Studios showed how players can acquire an Intellect Devourer as a pet. The character trying to win over the creature had to make a handful of correct rolls to safely interact with it. We don't know how long this creature would stay in the party or if it turned on them.
This gave us a brief rundown of the endless possibilities that can occur in Baldur's Gate 3. You can do the same with an Owlbear encounter if your character has experience handling animals. However, the team hasn't fully revealed the correct route to get there with mom Owlbear.
Do pets die?
We don't know if they're gone forever when they die or if a simple wake-up spell brings them back. Larian Studios didn't go into too much detail about a familiar's flexibility and depth. However, there are several possibilities to add them to your group. You probably have to keep your eyes peeled and pick the right choices to add them to the party. One wrong move could prevent them from reaching you.