Carfentanil is a powerful synthetic opioid primarily used as a tranquilizer for large animals, such as elephants. It is approximately 100 times more potent than fentanyl and is not intended for human consumption due to its extreme strength and potential for overdose. Due to its potency, even a small amount of carfentanil can be lethal to humans. It has been associated with the opioid crisis, as it can be mixed with other drugs, increasing the risk of accidental overdose. Awareness and caution are essential when dealing with substances containing carfentanil.