The process for this one was a bit complicated. First I generated an image that looks almost the same as this one, but smaller and with Dash having an extra leg. PNG info:
rainbow dash, intricate detail, countershading, vibrant cinematic lighting, fluffy, (rusty:0.7), Convoluted, Precise, trending on 500px, depth of field, pony nanopunk (rendered in maya:0.8) by F. Scott Hess Sam Spratt Greg Hildebrandt
Negative prompt: (bad anatomy compression artifacts (bitcoin:0.4) (salvador dali:0.5) CCTV surveillance sex penetration:1.2) ugly poor quality deformed (distorted:0.9) nft
Steps: 20, Sampler: Euler a, CFG scale: 7, Seed: 3750617228, Size: 512x512, Model hash: f74245c872, Model: pony-soup-v2
By chance, re-generating the image at 19 sampling steps instead of 20 fixed the extra leg, but it made other aspects of the image worse. So I took both images and merged them in GIMP - taking the fix from the 19-step version and keeping everything else from the 20-step version.
Finally, I took the prompt from the original image and upscaled the fixed image in the img2img tab using the “Just resize” resize mode. PNG info:
rainbow dash, intricate detail, countershading, vibrant cinematic lighting, fluffy, (rusty:0.7), Convoluted, Precise, trending on 500px, depth of field, pony nanopunk (rendered in maya:0.8) by F. Scott Hess Sam Spratt Greg Hildebrandt
Negative prompt: (bad anatomy compression artifacts (bitcoin:0.4) (salvador dali:0.5) CCTV surveillance sex penetration:1.2) ugly poor quality deformed (distorted:0.9) nft
Steps: 20, Sampler: Euler a, CFG scale: 7, Seed: 3750617228, Size: 1024x1024, Model hash: f74245c872, Model: pony-soup-v2, Denoising strength: 0.2, Mask blur: 4