Oipuis is an intelligent monkey guard that resides in the island city of Marim. Oipuis is one of several guards that can appear if they talk to a monkey on Ape Atoll while in human form. He may appear along with several Monkey Guards.
He is similar to Padulah except that he cannot be killed normally. If he hits the player, the player will appear in the Ape Atoll prison. Other guards that may appear instead of Oipuis are Ouhai, Uodai, Duke and Uyoro.
Instead of the player killing Oipuis themselves, he can be killed for medium-sized monkey ninja bones by walking in a monkey form on the trapdoor in the warehouse. The player can then quickly taking the greegree off and wait for him to appear, until a gnome will come and finish him. The player can then re-equip the greegree and take his bones.
High level players can easily kill him by trapping him behind an obstacle and using Magic or Ranged.