If you're just trying to make the initial Red-Backed Fury, you'll need hybrids in some form.
One way you could do it is:

- Start with a common frog at 4444444
- Make a Bothersome Fungus X Filling Oyster Hybrid for +1U powder, use 3 in a mud for +3U mud
- Make a mud from 1 Shrinking Cap, 1 Raucous Conecap, and 1 Pickled Bonnet (+1R, +1S), use 3 times

When you're doing genetic keys, obvs you need to jump from one set of traits to another in one generation only, but if you're just making the initial starting frog it doesn't matter how many cycles it takes to make it!