An (aluminium) "danger for guard dogs" sign is the support on which Aj Roi painted Mr Burns, the owner of the Springfield nuclear power plant, from the famous cartoon "The Simpsons". 
 
Every fan of the series knows that Montgomery Burns, the boss of Homer, usually releases the guard dogs to get rid of nuisances.
 
In this work of modern art, the cold tycoon is immortalized in his typical  pose with his fingers joined, while, with a grim expression, he pronounces the classic phrase: "Release the hounds!"