Granny is very old and when she tells stories of her young life sometimes, they can be a bit long, gross, or boring (especially to Jimmy).
In her first appearance in "Granny Baby," Jimmy accidentally turned her into a baby. It was hard to handle her like that, considering that since she pooped in the diaper, she was wearing a lot of diapers and it just kept getting worse until Jimmy got Cindy to change the diaper. When she was a baby, Granny had a pooping problem and she always pooped in her diaper. Soon, her dirty diaper was changed and she later asked for another. She could talk, but her mind was immature and it made her act like a regular baby.
"Send in the Clones"
"Clash of the Cousins"
While not actually appearing, Granny has been mentioned as being in Reno at the time of the party.
- Granny Neutron wasn't the only Nicktoons character Phyllis Diller did the voice for, as she previously voiced Aunt Mitzi on Hey Arnold!