Appearance and Ability Edit
In late fall, the trees look dry and don't have any foliage in their branches. They have seeds comparable to acorns, and the wood is not as dark brown as normal trees, but of a much lighter brown color. The bark is thick and its pores filled with a soft, gel-like substance.
The tree makes good wood for both building or fire, but it violently and explosively sheds its bark upon being injured, resulting in deadly shrapnel. This defense mechanism is not instantly, but delayed by at least a few seconds in which the bark writhes and releases the explosive gel, before the explosion occurs. It makes the trees undesirable for any [Woodcutters] or similar classes. That defense mechanism is however disabled in below-zero temperatures, which makes it possible to cut the trees in winter.
The tree itself remains denuded after exploding the bark, the wood unharmed.
When Erin explored the Floodplains on her own, she encountered a grove of Krakk trees not even within an hour walking distance of her inn. She was warned by her [Dangersense] and stopped approaching that lovely small forest. When she threw something at the nearest tree, its bark exploded, and Erin knew to keep her distance. She then used the fallen branches to burn a nest of Shield Spiders.
When Toren was tasked by Erin to collect wood to burn in her inn's fireplace, he first tried to chop down an Amentus tree, but after that failure he turned towards the only other source of wood nearby: The Krakk forest. He felled a tree and dragged pieces of it to the inn, where it exploded when he tried to light a fire with it. The inn was destroyed in this explosion.
Erin could then ask the Antinium to build her a replacement inn. The wood they used to construct the second inn was built with denuded Krakk wood, and they took great care to remove all the explosive bark from it. Rags found a good use for the left-over bark and collected it. She later used the Boom Bark in Liscor's Dungeon when she was fighting together with Toren against the Armor-Golems.
That Krakk forest had been known to local people: The Watch had marked the place as dangerous after an enitre [Scout] team had mysteriously disappered; and the local Goblin tribe also knew to avoid the trees who meant 'absolute death'.