Start by creating a circle using elliptical shape tool.
Press Ctrl+T. Right click the layer and select warp.
Adjust the nodes to get the result as shown in the image below.
Double click the layer to open layer style window. Apply layer style with the settings shown.
Using pen tool draw the neck and face for the duck. Follow along the images below for exact shape.
Create additional shape to add detail to the duck.
Using pen tool create wing of the duck.
Create feet of the duck using pen tool.
Create eye of the duck using pen tool.
Select wing layer. From layer menu select layer style>>create layers.
Select both the layers and press Ctrl+E to merge.
Select eraser tool and erase the top left portion of the wing.
Similarly remove the stroke from other areas.
Add details to the feet and other body parts.
Create a new layer. Select a 2 pixel solid brush. Select stroke path with brush in path window.
Create a new layer. Create a circular selection using elliptical marquee tool. Fill the selection with a radial gradient.
Press Ctrl+T and squeeze it vertically.
Ctrl+Click the layer to get the selection.
Press Ctrl+Alt+D to feather the selection. Feather the selection by 20 pixels.
Press Ctrl+Shift+I to inverse the selection and delete the outer selection several times.
Apply a light gradient to the background.
