Hello, @Blossom . . . here are some things to get you started with conversation:
And also some animals he can imitate:
This will provide you with just about everything there is to know about what EMO can currently do and say:
To answer your question about the volcano achievement, you need to get him to display three flames by either shaking and/or telling him he is bad or other negative things.
Note that he has to show the volcano ten times before the achievement shows up in the app.