How do I make an entity like a zombie and make it no longer moves? But I do not want it to happen for all of the zombies
Use NMS. Override the move() (I think it has parameters) and the collide() if you want. But yeah, NMS is your best bet since it qualifies for both of your needs. If you don't know how to work with NMS, here's a tutorial. Sorry I couldn't explain things better, haven't done any coding projects in the past 3 months or so.