The Penguin's a Jinx (2) - S1-E4
Other mistake: Penguin says that his sleeping gas' effect lasts 18 hours, but Bruce in his shop woke after mere minutes (sure, the extreme temperature helped him regain consciousness, but something as potent to knock you out for 18 hours with a small whiff can't completely lose effectiveness just because your feet are getting a little hot). (00:20:15)