carfentanil

Carfentanil or carfentanyl, sold under the brand name Wildnil, is an extremely potent opioid analgesic used in veterinary medicine to anesthetize large animals such as elephants and rhinoceroses.

It is approximately 10,000 times more potent than morphine and 100 times more potent than fentanyl, making it one of the most powerful opioids available.

Carfentanil is typically administered in this context by tranquilizer dart. Humans use it as a recreational drug, typically by injection, insufflation, or inhalation.