Were you looking for the monster family known as Simulacra?
A simulacrum is a key item that allows entrance to Skirmish or Alluvion Skirmish areas. Only the party leader needs a simulacrum for the entire party to enter. They are consumed on use.
How to Obtain
Trade a Visage, a Faithful's Torso, and a pair of Faithful's Legs to Oston Eastern Adoulin (G-8) to obtain a simulacrum. These different components control different parts of the resulting Skirmish experience.
To obtain a simulacrum for entering Alluvion Skirmish areas, trade Oston a Eudaemon Item in addition to the above parts.
The following simulacra are used to gain entrance to Skirmish:
All items (37)