Granny is very old, eccentric and when she tells stories of her young life sometimes, they can be a bit long, gross, or boring (especially to Jimmy).
Granny is said to be over 60 years old. She has light Gray hair tied into a bun and wears glasses. She bares a strong resemblance to her son, Hugh. She wears a Green long sleeve dress with White lace and Black heels with White stockings.
As a baby she is bald except for a single brown curl on top of her head. She has big brown eyes and one bottom tooth. She wears only a diaper.
In her first appearance in "Granny Baby", Jimmy accidentally turned her into a baby in hopes of avoiding her rambling. However, things turned for the less when Granny began pooping her diaper, which she says she was wearing prior to the transformation. The situation continued to worsen until Jimmy got Cindy to change the soiled diaper. When she was a baby, Granny was uncontrollably soiling her diaper. While she could still talk and use big words, she still had the physical features and personality of a baby, such as crying when she was unsatisfied, bored, or required changing. Unfortunately for Jimmy and Cindy, this meant changing her poopy diapers.
"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.
- "Goo goo gaa gee! Uh, oh! - Granny Baby
- "Ooooo...I need my diadee changed!" - Granny Baby
- "Change me now! WAAAAAAHHHH" - Granny Baby
- "Ohhhh...clean my poopy!" - Granny Baby
- "He made me smile and my dentures fell out" - Send in the Clones
- Granny Neutron wasn't the only Nicktoons character Phyllis Diller did the voice for, as she previously voiced Aunt Mitzi on Hey Arnold!
- Granny makes another appearance in Send in the Clones when the perky Jimmy Clone spends time with her in the park. Unfortunately he made her smile so much that her dentures fell out of her mouth, so she went to his house to complain with the rest of the townspeople.