Paper Mario: The Thousand-Year Door Tips

Get a Jabbi on your side in Chapter 2!
I did this on accident when I was exploring the hidden shop in the great Boggly tree, but here:

During Chapter 2 when you find the hidden shop in the tree(Pungent's Shop). Go to the very back/end of the shop (the left side). You will see some white tree stump like things. Go behind there and Jabble will pop out! Choose not to beat him up and he will join you.

He is not added to your Puni army number in the bottom of the screen, and no special thing happens. He doesn't ever talk, and he helps you fight the other Jabbies! He is also at the end of the chapter when all the Punies are saying good Bye to Mario. He doesn't say anything there either.