table: [['no in series', 'no in season', 'title', 'original air date', 'production code', 'us viewers (millions)'], ['21', '1', 'a doomed christmas', 'december 10 , 2011', '121', 'n / a'], ['22', '2', "big dog on campus / dog 's best friend", 'january 16 , 2012', '122', 'n / a'], ['23', '3', 'monkey business / diary of a mad cat', 'april 21 , 2012', '125', 'n / a'], ['24', '4', 'dudley do - wrong / puppy unplugged', 'may 6 , 2012', '123', 'n / a'], ['25', '5', 'freaky spy day / dog tired', 'may 13 , 2012', '202', 'n / a'], ['26', '6', 'top dog / quack in the box', 'may 20 , 2012', '124', 'n / a'], ['27', '7', 'lie like a dog / cold fish', 'may 27 , 2012', '126', '2.3'], ['28', '8', 'pup daddy / candy cane - ine', 'june 3 , 2012', '201', 'n / a'], ['29', '9', 'bark to the future / lights , camera , quacktion', 'october 13 , 2012', '205', '1.8'], ['30', '10', 'happy howl - o - ween', 'october 27 , 2012', '210', '1.6'], ['31', '11', 'bark to nature / mutts and bolts', 'august 5 , 2013', '213', '1.9'], ['32', '12', 'dog house / time waits for no mutt', 'august 6 , 2013', '203', '1.6'], ['33', '13', 'hush puppy / quacky birthday', 'august 8 , 2013', '209', '1.8'], ['34', '14', 'love bird / bluff puppy', 'october 20 , 2013 (nicktoons)', '204', 'n / a'], ['35', '15', 'rat trap / agent of the year', 'october 27 , 2013 (nicktoons)', '207', 'n / a'], ['36', '16', 'barking tall / bad eggs', 'november 3 , 2013 (nicktoons)', '212', 'n / a'], ['37', '17', 'carbon copies / tuff cookies', 'november 10 , 2013 (nicktoons)', '214', 'n / a'], ['39', '19', 'tuff choices / sob story', 'tba (nicktoons)', '208', 'n / a']]
ref: A Doomed Christmas was the only Episode to Air in 2011 in this Season
template: [ENT] was the only [ENT] to [ENT] in [ENT] in this [ENT]