This beak lacks to front part, re-create it by a small part of the beak nearby and transform to the shape of that part, then blend back to the original beak.
step 3 of 10
Select the head of the frog, duplicate the selection, use puppet wrap tool to change the shape of the mouth to fit the beak
step 4 of 10
Place the beak to the desired position, seems like it quite fits to the mouth now
step 5 of 10
Create a layer on the frog layer, use color blending mode, then paint the same color of the chicken onto the frog
step 6 of 10
And now I cover almost the frog with chicken color using the same method
step 7 of 10
Start to make the feather: paint a bit darker color on the remaining part of the frog's mouth (using a layer with normal blending mode) by soft, low opacity brush.
step 8 of 10
Draw the smaller, lighter hairs by smaller, brighter, harder brush (pressure sensitive mode was used)
step 9 of 10
Cover some area on the frog with hairs (same method)
Extract the eye of the chicken and place on to the ear of frog, use eraser with low opacity to gradually erase the eye from the outside, blending it to the frog. The hue/saturation was changed a bit to fit the frog.
step 10 of 10
Use two layers on top of all layers, one used color blending mode, one used overlay blending mode. Use brush with green/purple colors to paint on the color layer. Use black/white brush to paint on the overlay layer to adjust the light and make vignette effect. Crop the image more tightly.