|A/K/A||The Birthday Girl|
|Age||8 - 10 years old|
|Friends||Violet Heaslip (Best friend, multiple episodes)|
Exposition Guy (Best friend, one episode)
|Family||Mother (unknown identity)|
|Abilities||Green greed-induced transformation, super strength, size alteration|
|Voice Actor||Pamela Adlon|
She is a ten-year-old girl who is greedy, selfish, immature, and sometimes cruel. Usually, she appears to be a innocent little girl to others. She does whatever it takes to acquire anything she may want, by using a faux-polite manner, big eyes, and a lisping voice, along with the the statement "Today is my birthday!" Whenever she is denied something she wants, she yells "Mine, MINE, MINE!", growing in height and turning a deeper shade of green with each yell until the owner of the coveted item hands it over in fear.
The only way to reverse Eileen's transformation is to persuade her to do something generous instead of something greedy, a trick discovered by Violet in the episode "The Birthday Girl", and used several times since then.
Elleen thinks that every day is her birthday, and such uses the excuse as a reason to get special treatment from anyone and everyone, usually to great effect. Because she thinks every day is her birthday, she thinks every party is her birthday party, every cake is her birthday cake, etc. She also greatly annoys Becky because of her lisp, using the "w” sound in words instead of “l” or “r”. e.g. “I wearned my wesson.”, "Today's my biwthday!", "What do bestest-westest fwiends do?". In addition to using it to get what she wants, she also uses her cute charm to get herself out of trouble, as shown in "The Wrong Side of The Law".
- Her powers are based on those of the Hulk, a Marvel superhero, though unlike the hulk, her powers are based on greed rather than anger.
- The Birthday Girl (episode)
- Slumber Party Pooper
- Tiny Big (cameo)
- Who Wants Candy?
- Monkey-Robot Showdown (cameo)
- The Wrong Side of the Law
- Earth Day Girl
- Birthday Town
- When Chuck's Mom Is Away (cameo)
- Sonny Days with a Chance of Showers
- Crime In The Key Of V (cameo)
- Where Have All The Villains Gone? (cameo)
- The Rise of Miss Power (cameo)
- The Birthday Girl's Monstrous Gift
- Gift Pony (cameo)
- Scary With A Side Of Butter (cameo)
- House Arrest (cameo)
- Say it Again, Eileen
- Fortune Crookie (cameo)
- A Few Words From Wordgirl (cameo)
- Putt With Honor
- Granny's Corner (cameo)
- Can't Touch This (cameo)
- In the episode The Birthday Girl (episode) she is first telling Violet that her kite is beautiful and asks to have it, Violet accepts. But Violet tells her that it's getting late and asks to get her kite back. Eileen says no because Violet gave it to her she even asks for the charm bracelet Violet is wearing but Violet says no and Eileen grows taller but sees Bob and stops growing taller and asks to hold him Becky says no then Violet stands up to her. Later Eileen grows taller and taller, grabs Bob and goes far into the city. Later Eileen gives Bob cookies then tells him to wear it. But Bob denies it Eileen tells Bob that she will give him cookies Bob nods he tries to escape but hears that Eileen got cookies he tries to grab one or more but Eileen shows him the dress (for him to wear it) Bob grabs it and wears it then Eileen yells "TEA PARTY!!!!!!!" when Wordgirl and Violet investigate her house they look at Bob's dress and sees monkey hair. Eileen buys ob a new dress Bob shakes his head. Eileen turns taller and taller. Bob wears it. Eileen later sees the biggest star she ever seen, she puts Bob in her pocket and climbs up the building. Violet finds a way to stop her telling her that they are best friends. Eileen gives her necklace to Violet the turns smaller and smaller but Wordgirl saves her and Bob. When Wordgirl turns back to Becky, Becky tells Eileen that she learned a lesson eileen says "I wearned my wesson" Becky corrects her. Eileen tells them that she has to sleep because, she also tells them everyday is her birthday.
- In the episode Slumber Party Pooper she first hears Violet blurting out "Party!" she says she loves parties. In the slumber party she rings the doorbell and has a lot of stuff in her hand. She later sees Bob and grabs him and wants to make over him. She later sings about her "birthday" she later gives the slumber party guests some cake and tells them the Wordgirl isn't so great she turns taller and grabs Shelby Joy, Tessa, Emma, TJ Botsford, Bob and Violet she walks into the city. Wordgirl tells he to stop which she denies. Wordgirl goes around her and makes her drop the kids and Bob she's holding. She keeps on yelling "Mine!" but Wordgirl tells her that Becky's slumber party is the only one happening but tells her to stay if she likes saying "Weally?" At the end she is seen sleeping in the whale sleeping bag.