The Arimeides are the equivalent of version 4 of the Grendels of Minimordor. They have many alterations from the standard grendel, the most notable of which is the extreme sexual dimorphism and receptiveness to a chemical called Melhite. The Arimeides bring along a pack of agents to make the Capillata nice and cozy for them.
The males use the sprites of the C3 Grendels (Grendel A), C3 Ettins (Ettin A), and Bengal Norns (Norn B). The females have varying sprites due to a high mutation rate of their appearance genes, and so don't require specific sprites.