Trolls were part of an ancient race of Mobians known to have founded the Second Great Civilization and to be famous for their mastery of crystals. They are apparently quite grotesque in appearance and have large pointy ears, claws, and long tails. Relic the Pika studied and was fascinated by their civilization prior to taking up residence on Angel Island. At least some of them were proficient in magic, including the only known modern members of the species, Wendy and Walter Naugus. (SU: #70; StH: #276)
In ancient times, the Trolls mostly resided in a land called Pancardina, though their culture was felt worldwide, bringing about a new age of prosperity and order with their cystalline magic. They mined crystals that increased their magical powers, with one of said mines-the Hidden Palace Zone on Westside Island-still known to exist even in the modern day. The Trolls era was ended by a catastrophic event that blasted Pancardina into a series of islands, with the Trolls being all but wiped out overnight. (SU: #88)
- Given the traditional grotesque appearance of Trolls in most fiction, and the fact that SU: #70 mentioned their affinity for crystals, it was believed that Walter Naugus is a Troll in the Post-Super Genesis Wave Timeline continuity, whereas previously he was a fusion of three Mobians from different species. This was later confirmed by Ian Flynn, who also hinted at plans for Naugus to have relatives that were awaiting editorial approval or dismissal. () Flynn has also indicated that Trolls are virtually extinct, with the Naugus Twins possibly being the only remaining members.