Gertrude, or otherwise known as Pookie by Phil, is Arnold's grandmother from the Nickelodeon Nicktoon Hey Arnold!. She is the wife of Arnold's Grandpa Phil, and they have known each other since childhood. They had a relationship like Arnold and Helga when they were young. Gertie was mean to Phil (although in more extreme ways, like putting thumbtacks in his seat, dunking a part of her hair in ink and telling the teacher Phil did it, etc.) Grandma Gertrude runs a boarding house with Phil. Most of the boarders think she is crazy, because in every episode, she has a different theme that can be seen in her clothes, the way she talks, and the food she prepares for the boarders. She often is used as a philosophical source, especially with Arnold, through the use of metaphors that are usually not understood.
Gertrude usually acts younger than she appears. She taught Arnold self defense in one episode and helped him save a turtle from the constant torment from the elementary school children in another episode. She is often the only person who understands Arnold. She is very upbeat, and takes any situation with the same enthusiasm as any other. This was best shown in "The List," where Arnold failed attempts at having "the perfect Saturday" are comparted with Grandma Gertie's attempts to get her piano moved into the house. In the end, she has the piano put on the roof (where it stays for the rest of the show), and she and Arnold share a song about how you shouldn't let the little problems get you down.
She has a habit of mixing up holidays in holiday episodes of the show. For example, during Arnold's Christmas, she says "Happy Fourth of July everybody!" She plays the piano; and during holiday episodes, plays seasonal music, but confuses it; she played Christmas music in the Thanksgiving episode.
Grandma Gertrude and Grandpa Phil are the parents of Arnold's dad, Miles.
Examples of Grandma Gertie's wacky outfits and acts include the following:
- In "Eugene's Pet", Grandma Gertie dresses as a mermaid and serves fish.
- In "Arnold's Thanksgiving," Grandma Gertie gets the entire family to dress as important figures in American history in celebration of the Fourth of July. It's noted that she celebrates Thanksgiving on the Fourth of July. However, in the end, it ends up a normal Thanksgiving (with fireworks).
- In "Parents Day," Grandma wears her karate outfit throughout most of the episode, and is cooking miso soup.
- In "Summer Love," she sees a nudist beach. She then takes off her suit to join the nudists, scaring them away.
- In "Family Man," she dresses as Mary, Queen of Scots. While Mr. Hyunh is pretending the boarders are his immediate family, she pretends she's also Mr. Hyunh's sister.
- In "Rhonda Goes Broke," she dresses up as a Spanish Conquistador and gets on top of the table saying "I claim this dining room in the name of Spain" while every one in the boarding house is having dinner.
- In the April Fools episode on April 1st Gertie runs into the house screaming "Happy Groundhogs day I saw my shadow which means..." and Arnold and Phil continuing non-too ecstatic saying "12 more days of Christmas". She puts up Christmas decorations and takes Arnold to the dance in a sleigh.
- In "Save The Tree", Grandma wears a Tarzan suit.
- In "Girl Trouble", she wears a kimono.