The term 'adders cousins' refers to the family of venomous snakes known as vipers. The four-letter acronym ASPS stands for 'Asp and Viper Species, ' which includes the adders, vipers, and pit vipers. These snakes are found in many parts of the world, including Europe, Africa, Asia, and North America. They are characterized by their long, slender bodies, triangular heads, and heat-sensing pits located between the eyes and nostrils. They are also known for their potent venom, which can cause severe pain, swelling, and even death if not treated quickly.