Here's the finished concept art for the Brokers, which comes courtesy of Intrastele, who you can visit over here:
https://twitter.com/IntraStele
https://www.instagram.com/intrastele/

I'm really pleased with how this came out, and I'm very excited for the upcoming story that will introduce the Brokers in their true form! If you'd like to see higher resolutions or check out the WIPs, go visit the Patreon post over here: https://www.patreon.com/posts/48507030

THE FOLLOWING IS CLASSIFIED UNNI INTELLIGENCE FOR AN UPCOMING OPERATION - PROCEED AT YOUR OWN RISK

On the left, we have the front and back views. Some noteworthy features are the muscular locomotion tentacles situated beneath the body, which are used for walking and swimming, along with the four manipulator tentacles which are used in lieu of hands. The powerful suckers on these limbs feature sharp hooks used to provide more grip when catching slippery prey or holding objects, which can be retracted like the claws of a cat. Trailing behind the Broker are a pair of blankets formed from a thin, durable membrane of tissue that is decorated with colorful patterning and large eyespots which would have helped ward of predators in their prehistory. These billow out behind them as they move through the water, and can be manipulated using small tentacles that are attached to the mantle. These tentacles are rich in nerve endings and are used primarily for handling food and inspecting objects in detail. They also have taste receptors, performing the function of a tongue.

Much like cuttlefish, Brokers have a limited interior support structure akin to a skeleton that evolved from the external shells of their ancient forebears. This includes a protective braincase in the mantle, along with a structure in the torso that is used for anchoring the muscles in the manipulator tentacles, as well as a rudimentary spine made from cartilage that allows the Brokers to stand upright during their brief excursions onto land. Having evolved in the warm shallows of their homeworld, it is likely that their ancestors may have pursued prey out of the water and into rock pools during low tide. Brokers are able to absorb oxygen through their skin while out of the water, but only for a limited period of time before they run the risk of drying out and asphyxiating.

On the right are three busts with examples of different skin colors and regional variants. Upon the mantle are decorative fins and crests, their appearance varying between different geographic groups. Broker skin is covered in chromatophores, complex organs that are controlled by muscle groups that allow the Brokers to change the pigmentation and patterning of their skin. This originally evolved as a camouflage mechanism, but gradually developed into an involuntary one that facilitates social displays. Happy Brokers exhibit soft patterning with bright, pastel hues, while negative emotions such as anger or disgust may be expressed through sharp, contrasting stripes.

Broker eyes feature a horizontal pupil that is adapted for providing clear vision in an aquatic environment, but that is not to say that they do not have excellent visual acuity on land, too. Their lips conceal a sharp beak made from cartilage that is used for chewing food, comprised of an upper and lower mandible that function in a scissor-like fashion.