The horned spider-tailed viper (Pseudocerastes urarachnoides), a Near Threatened venomous species of the family Viperidae endemic to the Zagros Mountains in western Iran, is renowned for its unique caudal luring adaptation that mimics a spider to attract prey; the species was studied and described as the spider-tailed viper Pseudocerastes urarachnoides by Bostanchi, Anderson, Kami, and Papenfuss in 2006. This study reports previously undocumented low-elevation habitats of P. urarachnoides in Kermanshah Province, western Iran, where field surveys recorded geographic coordinates, elevation, slope via GPS, and environmental parameters (e.g., temperature) using thermometers, with specimens safely handled using hooks and tongs. These new sites differ markedly from previously reported localities: vegetation is sparse and dominated by annual herbaceous plants and scattered low shrubs with a complete absence of oak trees; substrates consist exclusively of limestone sediments; elevations range from approximately 650–700 meters above sea level (substantially lower than most known records); and slopes are extremely steep, reaching up to 90° (near-vertical rocky mountain faces). Observations were made between 09:00 and 11:00 under an ambient temperature of 27 °C, aligning with the species' activity patterns during warmer morning hours. These findings significantly expand the known ecological and elevational range of P. urarachnoides, highlighting its greater adaptability than previously assumed; the open structure, light-colored limestone substrate, sparse vegetation, and, particularly, the steep-to-vertical slopes likely optimize caudal luring efficacy for ambush predation while enhancing camouflage against visually oriented predators and prey. However, these vulnerable low-elevation habitats face severe threats, primarily from road construction, which causes direct habitat destruction, ecosystem fragmentation, and restricted resource access, potentially accelerating local population declines. This study underscores the urgent need for targeted conservation measures, including protection and monitoring of these newly discovered steep-slope, low-elevation populations in Kermanshah Province.