An encyclopedia-style illustration of a diamondback terrapin (Maclemys terrapin macrospilota) drawn with a 4B pencil, Kuretake Zig Mangaka 01, white Sakura gelly roll, and a cool grey 4 Winsor and Newton Brushmarker.
Prints available here:
https://www.artstation.com/prints/art_poster/lL4b/diamonds-are-forever (with the species caption)
https://www.artstation.com/prints/art_poster/jmqW/diamonds-are-forever-without-the-species-caption (without the species caption)