I wasn't sure where to post this, so if it's in the wrong forum, please let me know!

I was thinking about doing some art for the members of Lioden, and I have a really cool app on my tablet that's very similar to other color-by-number pixel art apps (it's called Cross-Stitch World), but it allows me to make my own designs just by simply uploading a photo, then adjusting the pixel density and size of the canvas, how many colors I want, and then coloring it in afterwards.

I'm wanting to do this for other people's lions, but I'm not sure if it's allowed or not because well, the original artwork isn't mine, I'm just basically making it more pixelated lol.

Here's an example of a headshot of my current king:


I'm also wondering if I can charge anything for doing something like this, if at all? I know that I obviously can't charge for the artwork itself, but what about the time spent to complete it? Depending on whether someone wants high/low density pixels and a high/low amount of colors, it can possibly take a half hour to several hours to complete.

Lol anyway, thanks in advance for reading and answering my questions. I hope I didn't ramble too much.