Goo



Goo, also known as Toxic Water, Acid, and Hazard Liquid, is an environmental hazard present in both Portal and Portal 2. It is Red, Green, and Brown swirled in appearence. Any contact with Goo will result in continuous damage, resulting in player death. It is usually present in order to provide a penalty for failure, and to ensure that players are precise with their movements and positioning of their Portals.