Here you goo! I hope you like it :) It was my Big Project over Christmas break and I'm really happy with how it came out, although I intended to get more backgrounds done (some ice floes and dark rocky earth broken up with magma and stuff, and also a more detailed background to accompany the nursery lines) but ran out of time. Hope you like this anyway! I've been so excited to share it!
Inside, you can customize the hyena to either have fuzz (as pictured above) or a full-on mane. Wasn't sure which you preferred for adults, since your original lines had manes. Nursery lines only have fuzz, but I'd be more than happy to add extra stuff at any time if you like my entry enough (more backgrounds/improved backgrounds, edits/additions to palettes, etc.) I also added two different types of mana arm bands: one with two gems as pictured in your original MGH adopts, and another arm band with only one gem. Nursery lines can be customized with either type as well.
Brush used for adult and nursery lines was a size 3 Round Pixelated Pen tool with Opacity set to 70 and Smoothing set to 50%. (For your line-editing/altering reference)