Techniques:
Used 128x128px canvas with predefined pico8 palette of colours done in GraphicsGale.
Placing contours and basic colour maps into the picture in the right half of it.
After gross colouring, shading took place and when finished, I mirrored the right part to left.
Following steps were to replace light colours with dark ones and check the border between light and dark side, including the modification of reflection in left eye.
Finally I add some water reflection effect and here we are :-)