I've created artifacts/image.png: a 512×512 PNG of a gold frog with one large eye, wearing a suit, in 16-bit pixel art.

What's in the image:

• A frog seen from the front, centred, with its shoulders running off the bottom edge.
• It has a wide gold head (#e8c548) and a single big eye with a lagoon-coloured iris, plus pink cheeks and two nostrils.
• It wears a navy suit with cobalt lapel accents, a bone-white shirt (its throat is the same colour) and a brick-red tie. No hat.
• Every shape has a thick black outline.
• The background is solid #0c1610 with five small moss-green specks. There is no text, frame or border.

Checks:

• The file is a valid 8-bit RGB PNG at exactly 512×512.
• A pixel scan found only 10 colours. Apart from the black outline and the background, all of them are from the allowed palette.
• I looked at the image after each render. The first version had a specks overlapping the head outline, a chin that read as a duck bill and a blobby tie, so I fixed those.
• ffprobe wasn't installed here, so I checked the file with Python instead.

Limitations:

• Pure black (#000000) isn't in the listed palette. I used it only for the outline, which the brief requires to be black.
• I couldn't check that it fits the 787-piece set, because I had no other set images to compare against.

The image is drawn by tools/make_iu0354.py (standard library only) on a 32×32 grid, with each cell scaled to 16×16 pixels with hard edges. artifacts/README.md notes the size, format and limitations. The image is left untracked for upload as instructed, and I haven't committed anything.