Monster

Monsters are the non-player, attackables NPCs in OSO

Tutorial

 * Mash Apes (aggressive)

monkeys covered with dark brown fur and malformed arms, with fists hard as stone. Usually found in packs (of 3 in the tutorial leve)

Plains
Drop : Fur
 * Herbivores (non aggressive)

Forest
Drops : Fangs, Dog Fur Drop : Poison Blood, membranes
 * at night
 * Wild Dogs
 * Flying Bats

Quarry
Drops : Stone Scales Drops : Rock Crab's meat
 * Armadillos
 * Rock Crab.

Boss : Sandman. physical defence is high

Forest
Drops : Big Boar's Meat, Fangs, Big Boar's Fur. Drops : Goblin's Horn Drops : Blue Jelly
 * Big Boar
 * Goblins
 * Slimes

Further :
 * Mill Bird
 * Grey Rat.

Crystal Cave

 * Monsters :
 * Poison Dozers (Centipedes, 50cm wide)
 * Boss : Acid Dozer (like Centipede but x3 bigger). Saliva is acid
 * Drops (for the 2) : Venomous Insect's Shell, Acid Liquid


 * Collection points
 * Iron Ore
 * Fossil (random rare chance ?)

【Crystal Tree】's Garden
The room behind the boss area. Unlike the rest of the cave, has an open ceiling and light floods from above. Contains a garden of flowers and a giant crystal tree, of which the players can harvest one branch as a reward.
 * Crystal Tree's Branch 【Important Item】

Wetlands

 * Moore Frog
 * drops : 【Frog's Stomach】


 * Mold Slimes
 * Non-active
 * Drops : 【Strongly Acidic Jelly】


 * Will O Wisp
 * Non-active
 * if killed :
 * drops 【Phosphorous Soul Crystal's Fragment】 (need 5 to make a full crystal)
 * Instead, by giving items to a non-hostile Wisp, it gives.
 * drops : 【Phosphorous Soul Crystals】, 【Phosphorous Soul Ore】 (rarely)


 * Treant (strong mob)
 * drops : Treant Wood


 * Darkman (boss)