I made the image and saved it as artifacts/image.png: a 512 × 512 PNG with 11 colours. I looked at the rendered result and fixed two things: the bandana knot was floating off the head, and a highlight on the forehead was covering part of the black outline.

How it was made: a Python script colours each square of a 32 × 32 grid, then scales it up 16 times without blending, so every pixel shows as a hard-edged square. There's no anti-aliasing, blur or gradient.

What the image shows:

• Character: one lagoon (#4ecac0) ghost, facing front and centred, with pink cheeks and a small "o" mouth.
• Eyes: glowing phosphor green with a bone-white centre.
• Bandana: brick red with bone dots, and a knot with tails on the right side.
• Robe: navy, with a gold V-neck trim and cobalt fold highlights. The shoulders reach the bottom edge.
• Outline: thick black outline (one grid pixel, which is 16 px at full size) around every shape.
• Background: solid #0c1610 with a few small moss-green specks. No scenery, text, logo, frame or border.
• Palette: only colours from the allowed list, plus black for outlines and the background colour.

Unmet requirements: none that I know of. Two limits:

• The shading is flat, because the palette has no darker shade of lagoon.
• I couldn't check whether it fits with the rest of the 787-piece set, because no example pieces were supplied.

The script is tools/gen_iu_0365.py, and README.md records the size, format and these limits. Both are new files I haven't committed. The image itself is left uncommitted, as required.