fencedin
Skeletron Prime
So Mud is one of the more awkward materials, you need dirt first off, and when you extract dirt you get seeds, and Jungle grass seeds are among those, which in my playing (its been a while) I only found like 1 after several stacks of dirt, you then take 50 dirt blocks, a bottle of water, while standing near water to craft 50 mud, its a bit complicated but its balanced so you can't just turn dirt to mud, otherwise you'd be able to get jungle materials really early on. I think it needs some tweaking personally but it is what it is.
I hadn't realized that I never removed 'being next to water' as a requirement for this recipe. Fixed now. And yes, I changed mud so you would have to work a little for a jungle biome, just like the rest of the biomes.