Esther DeGroot originated as a character in Scary Go Round and later became one of the lead characters of Giant Days.
Known sometimes as "Dark Esther" due to her "goth-girl" style, she was a grammar-school classmate of Erin Winters, Sarah Grote, and "The Boy" Eustace Boyce. Esther collaborated with Sarah to produce a fanzine entitled Guns for Eyes: formerly "Slash Don't Stab"[1], which also had music reviews by Shelley Winters (writing as "Dr Lady Sounds").
At some point during her grammar school days, she worked at an unorthodox pet store, and sold Comrade Bat to Shelley Winters.[2]
For a while Esther was romantically involved with The Boy, and the couple lost their virginity in a caravan in Wales, during a trip made in a failed attempt to get Tim Jones back from his exile. They briefly continued a long-distance relationship after going off to different universities, but this did not last long; the breakup is reported to have happened eleven days after she started at the university.
In college, Esther soon found a new circle of friends, becoming very close to Daisy Wooton and Susan Ptolemy, who had dorm rooms near hers. A group of stuck-up "mean girls" tried at first to recruit her into their friendship group, on account of Esther having been head girl in school as they were, but she found nothing in common with them and they soon became enemies instead. Erin, freshly returned from Hell, made a brief appearance to help Esther and her friends in one of the dizzying array of adventures they had within their first few weeks of college, adventures which are still being chronicled now. (Although Giant Days takes place a number of years earlier than other current John Allison comics -- it's in the gap between Scary Go Round and Bad Machinery -- no indication has yet been given of what becomes of these characters after this.)
Esther was listed at #3 on "Fresh Meat: The 25 Hottest First Years" at Bantserve, a website run by some guys who attend the same university as her. She was not pleased at this distinction.