Here is a website that I have found useful when I think I've heard that bit from some other song. I've linked it to Tech's page where it list every sample he's used in any song he's ever made.
They're all true - I don't think there's much known about Isaiah in Verse 2 but like somebody else mentioned, Verse 3 is about Brian Dennis. According to some lyrics explained on RapGenius, Verse 1 is actually about Krizz Kaliko himself as well.
Damn, I hope he doesn't. Maybe just release a teaser of it with the part with the text he already leaked (Look it up on his instagram or on genius where I put the lyrics up too).
I don't know who transcribed those lyrics, but they did a pretty terrible job of it.
Fun fact: this version of "The Beast" is the demo that was included on the promotional Everready sampler disc. Here, I've made a temporary download link.