The Warp Tool lets you warp and distort any part of your image. Select the brush type and drag your cursor around the region you want to distort.
Brush Types:
Brush Settings:
Smooth
Distortions can sometimes produce sharp or jagged edges. The Smooth tool will smooth out the distortions across the entire image and reduce jagged edges.

Reset
You can undo all distortions by clicking the Reset button.