I think my figure of speech is a little off. Almost sounds like I'm extracting escargot or mussels. There's nothing wrong with staying in your shell. But it can deprive your team/class members of valuable insight that they might not even know they needed. The goal isn't to change kids into extroverts, but to make them feel OK to communicate with others when it might be helpful.
With this particular kid, it was more about getting the other kids to be quiet long enough to give the Tiger a chance to speak. Sometimes a simple verbal cue like "what do you think?" is all it takes, but sometimes you have to spend time laying the groundwork: building an open environment, making sure you are communicating at their level, sometimes finding a kid with similar interest and pairing them up for a while.
I'm no expert, both of my kids are extroverts. But my mom was an educator, and I learned a lot from how she would deal with kids in group settings. It's far too easy for a lazy leader to only engage with the people constantly opening their mouths. But they can miss out on a lot of valuable insight if they ignore the quieter members of their group.
One last thing, and it's a little off topic, but you really got me thinking. When you say "it might be fun," you are meaning that even though you are not in the mood to talk, you still don't mind being talked to. Am I reading that right? That is really interesting. I had no idea that it didn't have to be a two-way street. I know for me, if I'm not in the mood to jibber-jabber, I'm not in the mood for somebody else's jibber-jabber either. It never even occurred to me that there would be people who like being talked to without any desire to say anything back. That's a real mind-opener. But it makes sense, right? I mean there are people who just like to talk, and don't care to listen. So it would make sense that there are people who honestly just like to listen. Man... Thanks for that!!