Tales of the Beanworld
Gran'Ma'Pa provides guidance and protection to the inhabitants of the Beanworld. In times of true crisis, Beans have called upon Gran'Ma'Pa for help, with unexpected results. Gran'Ma'Pa was instrumental in saving the Hoi-Polloi in issue 1, The Legend of Pop! Pop! Pop!.
Also, a troubled bean called upon Gran'Ma'Pa for help, and received a strange gift, becoming Heyoka.
We've also been shown how Gran'Ma'Pa produces a new generation of Beans. See issue 8, Deep down; down deep! for a full explanation.
Gran'Ma'Pa was not always mute. The backup story
Tales of the Goofy Jerks
tells part of the story of why Gran'Ma'Pa speaks through Sprout-Butts.