The Dewan arthropod was a scorpion arachnid species native to New Romulus (Dewa III). Like all New Romulan creatures, these scorpions had six eyes. The Dewan arthropod had powerful stings for smashing its prey but its pincers were even stronger. These stings were venomous. The scorpion preferred to ensnare smaller prey than itself instead of the active hunt. On New Romulus, the Dewan arthropods were found in the Vastam Peaks and the Paehhos Crater caves. (STO missions: "New Romulus: Vastam Peaks", "Overgrown Caves") On Nimbus III, Dewan arthropods were also known as "sand scorpions." The Dewan arthropods grew with age. (STO mission: "The Lost City of Paradise")
The Romulan and Reman people returned to New Romulus in 2409 after the radiation had diminished so far that humanoid life was possible once more. They began to explore the landscape and observe the wildlife. (STO mission: "The Search for New Romulus")
The Dewan arthropods developed hardened shells in response to the thousands of years of radiation on Dewa III.
The arthropods were common in the Vastam Peaks. Romulan scientists presumed that the scorpions preferred the higher elevation because either they evolved in a mountainous region or they had fled from an hitherto unknown "alpha predator." Romulans wandering in the Vastam Peaks were sometimes ensnared by Dewan arthropods, requiring rescue by military officers. (STO mission: "New Romulus: Vastam Peaks")
On Nimbus III, "sand scorpions" roamed the desert outside of Paradise City. Unlike their more singular cousins from the New Romulan mountains, the sand scorpions lived in groups of different ages and sizes. At times, they attacked and ensnared Starfleet and KDF officers. They made venturing into the desert a risky endeavor. (STO mission: "The Lost City of Paradise")
In 2409, Hassan the Undying held several sand scorpions in the arena in his stronghold, including an abnormally enormous specimen. They were killed when Starfleet, KDF and RFF officers were forced to fight them in his arena. In turn, the officers forced Hassan to abandon the stronghold. (STO mission: "The Undying")