Ketamine (which is also referred to as K, Special K, Vitamin K, green, and jet) is a tranquilizer (anesthetic) that has some medical use with humans but is more commonly used in veterinary medicine. Ketamine is a “club drug,” a hallucinogen, and a dissociative drug. Other common dissociative hallucinogens are PCP and nitrous oxide (laughing gas). When abused for recreational purposes, Ketamine is commonly snorted in powder form, or injected in liquid form.