Combine face layer from 4 source images, using flip horizontal and vertical.

Make the eye by taking copy of the lower section, flip it and rotate+mask.

Add cat eyes, flatten the layer and use warp tools to achieve the shape. Take copy of the lower section and use warp to make part of the face mask.

Make ears and upper body with the same concept.

Add all parts together and add the bob cat skull (needs some scaling and masking) with a blend mode to achieve some extra shape and shadows for the face mask.

Add background, fix the upper body section and minor flaws here and there.

Flatten image when it's ready, take duplicate, use render/lightning filter to get yellowish/orange colour and some shades.. use blend modes and masking to achieve final colours.

Use burn tool for the face edges to soften white lines.

Background is made from the original 4x4 layer with eyes, just stretched and colourized.