David MacPhailauthor : David MacPhailDavid MacPhail Book SeriesThorfinn and the Putrid PotionThorfinn and the Terrible TreasureThorfinn and the Awful InvasionThorfinn and the Dreadful DragonThorfinn and the Rotten ScotsThorfinn and the Disgusting FeastThorfinn and the Gruesome GamesTop-Secret Grandad and MeDeath by SoupThorfinn and the Raging Raiders