Ncp abilities

The npc spawn egg is one of the coolest objects that you can get by using the give command.(give @p spawn_egg 1 51). You can talk to them,they can ask you questions but it gets kind of boring after a while. What if they could dance. What if they could push buttons. They should have changing dialogue, once you answer their question it should automatically switch to another dialogue that you have set up and new buttons.