Hi!
I wandering if there is a way to change the behavior of the minecraft vanilla mob.

My idea is to add a bed for the cat, and when the cat is damaged or he simply wants to sleep, goes into the bed.
There is a way to add this behavior to the vanilla cat?  

9 hours ago, Yurim64 said:

There is a way to add this behavior to the vanilla cat?

Sure! What I would do is create a new Goal (there are a lot of similar vanilla goals that you can draw inspiration from or even extend, such as CatSitOnBlockGoal and MoveToBlockGoal) that implements the cat behavior you want. Then you can add the goal to the goalSelector of the cat in the EntityJoinWorldEvent event.

Thanks a lot!