Ellen is essentially a mad scientist, particularly when it comes to flora and fauna, born and raised in Nod's Limbs alongside her younger twin brother, Edgar. When she was about seven years old, her parents departed on an "around-the-world holiday" and never returned. The twins cause a lot of mischief and mayhem by pulling elaborate pranks, often in the form of booby traps, both on each other and the residents of Nod's Limbs. She has an impressive collection of poisonous and carnivorous plants, which she sometimes uses in her pranks.
Ellen is very intelligent and can solve problems quickly when the need arises. While more level-headed than her brother, she can also lose her temper very quickly. She is also very athletic, being capable of out running several Nod's Limbsians. She is quick to plan pranks, especially when they involve her archenemy, Stephanie Knightleigh.
During the course of the series, Ellen and Edgar discover dozens of secrets about their seemingly perfect town, develop relationships with their mysterious groundskeeper, Ronan Heimertz, and their strange, one-eyed pet, Pet, and become the heirs of Augustus Nod.
Ellen was born to an unnamed couple two minutes and thirteen seconds before her brother. Little is known about her life with her parents except that that they made their mother suffer for hours during labor due to Ellen fighting with her twin brother to be the first born ("Rare Beasts"). Seven years later their parents abandoned the town for unknown reasons, leaving a note for their children saying that they went on an "around the world vacation", leaving her alone with Edgar, Pet and their creepy housekeeper, Heimertz. She and Edgar kept themselves busy by pulling pranks on the townsfolk (and each other), playing "Hide, Seek and Subdue" and avoiding Heimertz.
Leadership: Ellen often acts as the dominant leader twin.
Botany: Ellen is a mad scientist in the world of botany.
Quick-witted/Skilled Liar: Ellen shows great aptitude for lying and is quick to make up stories whenever something goes wrong:
Intelligence: Ellen is very smart and can solve problems quickly when necessary.
Cooking: Ellen apparently knows how to cook as she is usually the one to cook both hers and Edgar's meals.
Singing: Ellen likes to sing, but she does it so bad that everytime she attempts to sing Edgar has to put on ear plugs, although she insists in that she sings better than anybody. She and Edgar typically burst out in song or verse.
Ellen is tall for her age and skinny, with chest lenght black hair tied in two limp pigtails with two dark red bows, has an angular face and wide bulging eyes and grayish pale white skin. She lost the fingernail of one of her pinky fingers in an accident that involved a claw hammer and the head of Stephanie Knightleigh's favorite doll.
In the TV series, Ellen has bangs like Edgar's, although hers are only visible when her hair is wet, meaning that she usually keeps them away from her face.
Her regular outfit consist on stripped footie pijamas which used to be red and white, but due to years of not being washed they changed to grey and a rusty shade of red. She wore a mint green dress, which was made for her by Madame Dahlia, for Heimertz and Madame Dahlia's wedding, but she still wore her pajamas under it. ("Hot Air")
Ellen is tougher and more independent than her brother, she is a quick thinker and is skilled in problem solving, although she is also very impulsive and prefers to charge right in rather than stop to plan. She has a fiery temper and is prone to violent outbursts when angry. She is a master storyteller and bluffer. She is very affectionate with her plants but has trouble showing affection to people, let alone her brother. She has a manipulative and cunning nature and exceptional intelligence. In the beggining of the series, she enjoyed other people's suffering but after making friends and gaining a surrogate family she has become much nicer and has learned to love and care for people.
Both Edgar and Ellen love booby traps and pranks. Funnily enough even though they often fight, they are helpless when going solo. ("Pet's Revenge") Ellen is a tomboy and hates pastel colors and anything girly. ("Tourist Trap")