This article contains plot details from the latest book.
“And at the ogre Peace Summit, she'd been introduced to Empress Pernille, who reminded her of a tiny Muppet with a potbelly, fuzzy skin, and an upturned nose.”
—Narration, in Book 7: Flashback
Trolls are one of the intelligent species. They age in reverse and are introduced in Lodestar. Their leader is Empress Pernille. Empress Pernille was one of the leaders that attended the summit at Lumenaria. She is described in the quote above. However, this is not how all trolls look because Empress Pernille is an older troll. It was also mentioned in Exile that trolls do not value animal life as much as elves, meaning they are not vegetarians. It could also mean that they eat certain types of animals, but also value some different animals.
Trolls age in seven stages, stage four being the prime stage because it's when they're both strong and have a sharp mind. Stage one is when the trolls have no smarts or wits, but are very strong, making them extremely vicious. Stage seven is when the trolls are the least strong, but the most smart out of any of their stages.
Newborn trolls are born prematurely. Because of this, they are housed in hives until they are ready to hatch. These hives were attacked by ogres, causing the trolls to create an alliance with Luzia Vacker to use her property and concealment illusions to protect their hives. These hives were also used to save Luna and Wynn, the baby alicorns when they were born prematurely.
The Trollish capital is Marintrylla.