Troll

Trolls are a predatory species of giant who sometimes take over tribes of lowborn giantkin. There are several sub-species of trolls.

Known Troll Types
Trolls that are nearly obliterated but survive and regenerate from mere scraps of flesh can display bizarre mutations. One of these warped trolls is especially likely to arise if the creature regenerates in the presence of magical emanations, planar energy, disease, or death on a vast scale, or if its body was damaged by elemental forces. These mutated forms can also be produced and shaped by the ritual magic of evil spellcasters.

Common Troll
The most common type of troll has deep forest-green skin.

Venom Troll
Venom trolls are bulbous, with a deep green-blue skin tone with little pustules and boils on it. The torso appears to be swollen, its belly protruding beyond it. Out of the pustules and part of its body oozes thick green poison, and it sprays out from every wound they receive.

Abilities

 * Damage Immunities: Poison
 * Condition Immunities: Poisoned
 * Senses: Darkvision
 * Languages: Giant
 * Keen Smell
 * Poison Splash: When the troll takes damage of any type but psychic, each creature within 5 feet takes poison damage.
 * Regeneration: The troll regains health at the start of each of its turns. If acid or fire damage is taken, it regains no health and is only then able to be killed permanently.
 * Attacks:
 * Multiattack: The troll can make three attacks, one bite and two claw attacks.
 * Bite: The troll can make an attack with its teeth and giant tusks.
 * Claw: The troll can attack with its claws wolverine-style.
 * Venom Spray: Dealing damage to itself, the troll can release a spray of poison in a 15-foot cube.

Ice Troll
The trolls of Eiselcross, the Flotket Alps, and the Cliffkeep Mountains are presumably ice trolls. Able to grow to nine feet tall, these trolls have dull teal-blue skin and fur, elongated arms and legs, and a high-pitched, yelp-like scream. The claws of these trolls give off a cold mist when they strike a target.

Campaign One: Vox Machina
At some point during the pre-stream campaign, Tiberius attempted to disguise himself as a female troll in order to distract a couple of male trolls around a fire. The situation almost ended very badly for Tiberius had his teammates not come in to rescue him. Vex'ahlia shot off the one troll's dick, which then ended up being placed into Grog's Bag of Holding, where it remained for some time until it Grog pulled it out to offer it up and found it had rotted; it was finally thrown at someone as a distraction.

Vox Machina encountered a pair of trolls in a duergar warcamp controlled by a mind flayer; these Underdark-dwelling trolls had pupil-less, clouded-over, white eyes like the duergar. Using illusions, the party tricked the trolls into running off a cliff and dropping into the water below, where they were pulled under by an aboleth.

The party found more possible troll footprints among the duergar patrols on the approach to the Emberhold. In the sea of bone and obsidian between the Emberhold and Yug'Voril, a troll accompanied another small group of duergar, but that troll was decapitated by an extremely fast-moving abomination and pulled under the "sea" as it regenerated. And Queen Ulara was accompanied by a giant troll as she fled with an abducted Grog deeper into the Underdark.

Campaign Two: The Mighty Nein
The Mountain Makers fought and defeated an ice troll in the Victory Pit during the Harvest Close Festival in Zadash. The Mighty Nein soon afterward encountered a venom troll in the Labenda Swamp.

In the Explorer's Guide to Wildemount, set in 835 PD, there is an adventure hook around Jigow involving a clan of trolls led by an oni; the oni creates an alchemical infusion from trolls' blood that causes a horizonback tortoise to go berserk and gain the trolls' ability to regenerate after suffering wounds.

Dagen Underthorn mentioned that Eiselcross had "troll mutations up the wazoo," presumably ice trolls.