|— Name disclaimer —|
|This troll is not given a name in the series or novelization|
This unnamed Baby troll is a young troll that first appears in the episode "Chapter 4: The Sparrow Scouts", and plays a major role in "Chapter 5: The Troll Rock". The character also appears in the Hilda Tie-In Series, but not in the graphic novels.
As a baby, the troll is much smaller than an adult troll; not even half the size of Hilda and her friends. It has a round body with arms and legs, and like all trolls a long nose and glowing, white eyes.
Like all trolls, the baby troll petrifies into a rock when exposed to sunlight. When petrified, it resembles a round rock with a nose-like protrusion.
The baby troll is very wild and tends to cause a lot of chaos. How much of this is actually out of malice is debatable, however, since it is also possible the troll was trying to get back to its mother.
In "Chapter 4: The Sparrow Scouts", David finds the petrified baby troll near a Vittra tunnel, and since he doesn't recognize it as a troll rock, he decides to keep it for his rock collection. The mother of the baby is at that moment just outside the wall, near another entrance to the tunnels, so it can be assumed the baby used the tunnel to get into Trolberg. David takes the rock home, failing to notice that the rock begins to move at night and even grows in size.
In "Chapter 5: The Troll Rock", David brings the rock with him to The Ahlberg School as his project for parents night. Here, the troll comes to live when the lights are turned off for a documentary film, and wrecks the projector. When Ms. Hallgrim locks David’s rock collection, including the troll, in her desk drawer to prevent further incidents, the troll comes to live again inside the desk and tries to break out. This is what tips Hilda off that the rock is a troll. She, David, Frida and Alfur take the rock from the desk drawer and try to get the troll out of school before the sun sets, but fail. Once the sun goes down, the troll comes to life again and wrecks the projects before fleeing into the school’s ventilation system.
Around this time, the Troll’s mother also shows up at the school, having followed her child there. Hilda is finally able to catch the young troll in Ms. Hallgrim's office, and gives the child back to its mother. The mother then leaves, taking her child with her.
The plot of "Chapter 5" is also adapted into "Hilda and the Great Parade", where it gets combined with "Chapter 3: The Bird Parade" and "Chapter 7: The Lost Clan". In the book, David finds the petrified troll near the village of the Bragga Family. How the baby got into Trolberg is not revealed, though David remarked earlier that the wall in this part of Trolberg is rather fragile and crumbling. Like in the animated series, David takes the baby troll with him to school for a project, where the Troll wreaks havoc until Hilda is able to capture it and return it to its mother. The chaos caused by the troll allows Trevor to escape with The Great Raven (whom he captured for his own project).