take action that is intended to prevent trouble, but which actually brings it about
In Greek legend, Cadmus killed a dragon and sowed its teeth which sprang up as armed men. These men then killed one another, leaving just five survivors who became the ancestors of the Thebans.
RELATED IDIOMS :
chase the dragon
take heroin (sometimes mixed with another smokable drug) by heating it in tinfoil and inhaling the fumes through a tube or roll of paper.
Chase the dragon is reputedly a | translation from Chinese. The expression apparently refers to the undulating movements of the fumes up and down the tinfoil, resembling those of the tail of a dragon, a creature found in many Chinese myths.