The Fairly OddParents - 1x06a - Dream Goat!

While visiting Dimmsdale City Hall on a tour, Timmy and Vicky are shown the town mascot, Chompy the Goat. After seeing how depressed it looks, Timmy wishes Chompy free. The guards see Vicky messing with Timmy and notice Chompy is missing. They arrest Vicky and she is taken to jail. At first, Timmy celebrates this, especially after he is named the town hero and praised by everyone, including his parents. Not long after though, guilt begins to set in, and Timmy cannot sleep without having nightmares. Timmy must either fess up to his lie, or live in guilt and without sleep forever: a problem which becomes worse when Timmy begins making dangerous wishes in his sleep that Cosmo and Wanda must grant.