Instakill gas is the gas that erupts from the Forbidden Pits. When inhaled it causes instant death since it has lethal chemicals that disintegrate the lungs. four-eyed Squid-Bears are immune to this gas since they have special lungs that breathe both water and air. Special suits have been made to repel Instakill gas. Explorers use them when they are in the Forbidden Pits, along with a gas mask.