Quark is a sub-atomical villain in the Super Secret Secret Squirrel segment of the 2 Stupid Dogs series.
He destroys buildings and monuments by taking out the bottom atom making them into dust. He also got Secret Squirrel put into a cell in the asylum by entering through his ear and giving him a hostile suggestion. He then tells Secret Squirrel his plan to destroy Hoover Dam making a flood and then build an amphitheater out of North America where he will be a singing sensation. After Morocco Mole freed Secret Squirrel by removing the bottom brick from the prison wall, Secret Squirrel shrinks himself to deal with Quark. They chase each other to the shed in a construction site where some workers were having lunch. On their table was a dictionary where Secret Squirrel led Quark to the word that is his name. Secret Squirrel then states that Quark is a "hypothetical" sub-atomic atom meaning that he's an outdated theory. Quark didn't want to believe it and pursue his dream but he couldn't stop the inevitable as he was losing his limbs and eventually blew up in the tiniest nuclear explosion.