Progression of the battle
Goblins. Everyone knows these green creatures that have small humanoid structures, a wild personality, high reproductive rates- and no, they don't do anything sexual with females of other kinds– though it would have been pretty fun to see them do something like that— or not, anyway, they were goblins.
They were one of the simplest creatures that players killed and since they gave good Exp, people raided their villages in the forest pretty frequently.
They were found in the dungeon of Arrbo as well, so the dungeon was frequented by the players on a regular basis.
The Goblins weren't that great fighters or that strong creatures, but they knew how to set traps so they were sometimes a big headache to the players who had no experience with their tricks.