I feel to just shout Shitake

... I tried translating, I really tried.
I don't know how people like Soljashy and Moonspeaker do it.

That's 略して. The joke is that the portmanteau abbreviation of うんこ and キノコ would still be ウンコ, because キノコ ends with コ as well. How to render that in English is anyone's guess.

!Pteleports said:
I don't know how people like Soljashy and Moonspeaker do it.

It is my firm conviction -- supported, I believe, by a preponderance of the evidence -- that they are magic.

Well, you're in that list too.
Anyway, "shitshroom"? うんこ seemed a bit more vulgar than what I put in the translation.

One thing about japanese is that sometimes it is hard to find the pauses between words. In this case, the first two lines form the first sentence.

... Eesh. I was off a bit.
Well, thanks for solving the mystery.