The Community in more languages
Now the forum welcomes more languages.
You'll see a green translate button in comments and discussions to turn them into English
If you don't know how each of them can help you in your levels, I can help you: the blue cat is called Lyra - she converts some bubbles into bubbles with fairies in them, which I think you know what they do. As you level up Lyra more by renovating your house, she will give you more fairy bubbles in your levels.
The green cat is Eri, which imo is the most helpful: it charges some of your magic bubble which I think you know what does. If you manage to max Eri (by getting house chests of course), Eri can charge you THE WHOLE SPHERE! It is so good!
The red one is named Puck, you'll later find out that it can transform some of your bubbles into those that explode upon touching (I forgot their name). As you level it more, it will give you more explosive bubbles on the board.
The last cat, yellow, is named Leo. Leo transforms some of your bubbles from the board into star bubbles, which can increase your score by a lot if you manage to pop them. Same as other cats, when you upgrade it more, it gives you more star bubbles.
(NOTE: you can't choose which cat to upgrade after you get a house chest: the game will automatically give you an upgrade on Lyra, Eri, Puck and THEN Leo, in THIS ORDER, everytime you manage to get a chest like that)
Hope this helps :))