Three little pigs are working diligently to build their homes to protect them from the big bad Wolf in Huff N’ Puff™, the latest game in the player-favorite Lock It Link® series! During a riveting Free Games Bonus, Hard Hat symbols award additional free games and add frames to reel positions that are upgraded if a frame is already on that position. At the end of the bonus, the frames are replaced by a Straw, Wood or Brick house, depending on the upgrade, which the Wolf blows down awarding credit prizes and jackpots!