Role in The Crystal Prison Edit
Dimsel is first mentioned by Alison Sedge as the latter is boasting about herself while alone. In a tone of mock pity, she whispers that Dimsel has a face like a cow's behind and a wit to match.
Visiting town mouse Audrey Brown encounters Dimsel and her friends Iris Crowfoot and Lily Clover as they are gathering moss to line nests with. They have a friendly chat and Lily blurts out that Dimsel has a crush on Audrey's brother Arthur, much to her embarrassment. Audrey is amused and wishes Dimsel the best concerning her brother.
When Audrey meets Alison, she mentions Dimsel being attracted to Arthur, and then remarks cruelly that neither is a catch.
Dimsel is seen sidling up to Arthur and then dancing with him during Midsummers' Eve.
In the end, when Arthur and Audrey leave Fennywolde, Dimsel stares after the former sorrowfully.
Role in Whortle's Hope Edit
During the previous summer, Dimsel is very unpleasant and downright nasty. She constantly torments Young Whortle Nep and his friends, mocking them and their club the Wolf Killers. When she hears Whortle is planning on entering the Fennywolde Games, she scoffs and informs him that she is also and he hasn't a chance against her. Dimsel is tomboyish and athletic, so it seems she may be right.
Whortle and his friends make a raft for the game, only for it to be stolen and hidden by Dimsel. The girls work together to make a hideout of their own from an old abandoned burrow beneath one of the great oaks beyond the meadow. At one point, Iris comes crying hysterically to Whortle and explains that a monster has got Dimsel. The boys initially doubt her but she is so frightened that they could not fail to believe it. They find Dimsel cornered in the new den the girls had made, shouting taunts at the 'monster' that is in fact a wolf. Whortle and his friends manage to defeat it, only to realise that it was Todkin's drawing brought to life by the magic of the three watervoles who befriended Whortle. They wanted to give he and the other Wolf Killers the opportunity to live up to their name.
The games begin and much to the dismay of Whortle and his friends (who have, unbeknownst to him, been trying to give him the upper paw through cheating), Dimsel is ahead of him. For the raft race, she makes a great show of marching out dressed as 'The Savage Goddess', which is the theme of her raft. Isaac Nettle is appalled by her apparent blasphemy, and warns her that the Green will punish her if she doesn't repent. She only scoffs and disrespects him, much to the shock of all watching.
It is clear that Dimsel has a better raft than anyone else, complete with spikes that could ram into the crafts of the other entrants. Knowing that Whortle doesn't stand a chance, Samuel Gorse makes the difficult decision to give Dimsel the magical biscuit he had received from the watervoles that was to help him put on weight.
The race starts out in Dimsel's favour, as she destroys the rafts of others and hurls hateful insults at them. She even steals Twit's paddle when Jenkin grabs hers and tosses it to the shore in a fit of anger. But then, as Dimsel is almost at the finish line, Samuel's biscuit starts to take effect. To her dismay and horror, Dimsel begins to rapidly gain weight, to the point where her raft is capsized and she is pitched into the water.
Noticing the struggling Dimsel, Whortle tows her to the shore. She is now so huge that it is impossible for her to move. The fieldmice gather about her in wonder, believing it to be divine punishment from the Green Mouse, as Isaac Nettle had previously said that the weight of His wrath would come down on her. Only Figgy, Todkin, Hodge, and Samuel know that it was the biscuit that did it. Alison Sedge is in her glory taunting her rival. "You ain't fat, Dimsel - you're gigantic", she says in mock pity while patting her head, before capering off to find Jenkin.
An oversized domed nest must be built for Dimsel on the ground, as she is too large to fit in a regular one. 'The Savage Goddess' raft is recovered from the water and, after the spikes are removed, wheels are fitted onto it. Five burly fieldmice lift Dimsel onto it and trawl her to the Hall of Corn.
The Bottom family assure Dimsel that they will be close by if she needs anything... so long as it's not a pie, her mother remarks. This causes Dimsel to start weeping and her grandmother, with her usual lack of tact, says that even her tears are fat.
Later, during the Slingshot competition, one of the final challenges in the Fennywolde Games, Young Whortle decides to intentionally miss the target so Jenkin can win. The stone he slings goes flying and a piercing howl is heard from the Hall of Corn. It was Dimsel, with Whortle having successfully hit her on the bottom. But it is noted that since it is currently such a large area it was really no great feat.
Dimsel's colossal weight takes over a year to shed, and she never again doubts the existence of the Green. She becomes a much kinder mouse maiden as a result of her ordeal.