Add Mesh
Before you can create any deformations, you’ll need to add a mesh. With the image selected, either hit the Enter key or navigate to the Deform section of the inspector, hit the plus button, then select mesh. You’ll notice that a simple mesh is automatically generated for you.

Edit Mesh
You can edit a mesh at any time by using the Edit Mesh button in the Inspector or by hitting enter with the asset selected. Use the Pen tool to add, subtract, or move vertices.
Mesh Deform
In both Design and Edit modes, you can deform your mesh by entering edit mesh mode, and moving a vertex with the select tool. For a more natural experience, consider using bones.