Emm except that they are great?
Yes, they are not only pleasant to look at but also useful in the game!

After you get your first Pet the gorgeous Cat, you can see the little pink Paw icon on the top. Tap it to open the Pet menu.

Here you can choose from available Pets, change their appearance and name as well as feed them to take with you.     Now, when you will do something, your Pet will drop energy from time to time. Upgrade your Pet level by feeding it and taking it with you, and get more drops! 

P.S. Take your Pet with you to the Friend location to have a chance to get the water💧