Dwight is cowardly and has an unusual fear of harpoons, because of a dream (or wish) he once had where he was a whale and a lot of people wanted his blubber. He was sent to Wishing Well due to his excessive wishing which exhausted his godparent, and required him to be sent there to be rehabilitated and trained to face his fears and daily chores without magic, which he and the others failed miserably at.
He ended up in Wishing Well due to his Over-Wishing Disorder, and was easily frightened when he was put up against his greatest fear, a stationary harpoon gun. Molly did not seem to like him at all and constantly made fun of him. Eventually the three godchildren got fed up with their treatment at Wishing Well and plotted to escape, and the harpoon gun in the room where they had to face their fears was pivotal to their escape. This was actually their final test, and the three were deemed rehabilitated by Jorgen Von Strangle, who released them back to their fairy godparents. He then introduces Timmy to his godparent Irving before everyone celebrates the rehabilitation.