For correct anatomy according to the movie, use:
m-melvin,
grey skin, gnome, 1boy,solo,
Negative prompt: greyscale,
To be more precise use: black hair, gray eyes, plump,
Clothing:
grey shirt, grey shorts,
footwear,
For score:
I recommend you to have a look at the reference images
prompt: score_9, score_8_up, score_7_up, score_6_up, score_5_up, score_4_up,
negative prompt: low_quality, worst_quality, greyscale, text, watermark, 1girl, woman, pussy, female, female clothes, panties, pectorals, obese, muscular, thighs, bara, slim, simple background, expressionless, squat, fangs, big penis, collared shirt, chibi, shota, child, freckles, painted lips, mutilation, green eyes, blue eyes, clothes, thick eyebrows, earrings, tits, size difference,
negative prompt: greyscale, simple background, blurry, worst quality, low quality, earrings, female, 1girl, woman, pussy, panties, muscular, obese, pectorals, bara, facial hair, slim, chibi, shota, child, thighs, big penis, freckles, meme, navel, bad eyes, text, watermark, fangs, aged up, aged down, young, painted lips, pointy ears, size difference, mini person, collared shirt, bad_teeth, shirt, pants,
Note:
It is necessary to use gnome in order to keep its anatomy
Without "grey skin" has a normal skin color
Without "greyscale" only one color is maintained
Without "grey eyes" eye color is varied