EDIT: I've replaced the mockup image I originally posted with a new one. If you still want to see the old one,
here's a link. I had originally done the sprite using Queen Zeal's NPC palette from the final game. I knew the Prerelease version had different graphics, but I had mistakenly thought the palette was the same. It's not. So I redid the boss sprite with the Prerelease palette, and due to some of the value changes ended up making a bunch of little tweaks. I had also noticed a white pixel missing from Frog's eye, so this gave me a chance to fix that too. Everything else is the same as the first one I posted.
ORIGINAL POST:
Back with another mockup. This time it's the boss version of Queen Zeal that didn't make it into the final game. I'm really happy with this one.
What's different: Obviously I had to draw the sprite for Queen Zeal, since that isn't in the game at all. I had to bring the moon down a bit and change the arc of the horizon just a tad. The player sprites all needed to be tweaked a little. Ayla's outfit is slightly different, especially the tail/scarf part. Crono's hair is a bit fluffier on top and he's missing the white bandana tail on the back of his head. Frog has some mild edits to his arm, and for some reason the whole blade of his sword is missing. You can still see two white pixels from it coming out of the hilt.
The scrolling earth background was interesting. The version in the final game looks a bit scrambled in my opinion. I couldn't get it to match up with what's in this screenshot, so I took a look at how the tile graphics themselves are stored. Turns out they're in two big chunks that when placed side by side look like this:
From there I was able to figure out what the scrolling background would have looked like when this shot was made.
The blue circle around Queen Zeal is showing the earth graphics with an additive blending mode overlaid on top of the sky and black omen graphics. That's why the earth itself doesn't get brightened by the circle, and why you can see clouds around Queen Zeal's head.
Finally, here's the sprite by itself in case anyone wants it, followed by the Prerelease NPC sprite and the final NPC sprite for comparison:
You can see that the boss sprite outfit kind of matches the Prerelease NPC outfit.