I see you spotted the WR above Mandale, this was left out because I thought it was too ambiguous with another R directly below the first A of Mandale. In fact I decided that the highlighting of Mandale was not required at all given the amount to do in the grid, but the editor wanted it added.

I suspected Pop goes the Weasel was behind this fairly early on but “adaptation” suggested to me that it was going to be something less familiar. In the end, it turned out to be one of the very well known verses. I think “version” would have been a better word to use.

Also, “to electrocute” would have led to “fry”, I think, and would have made for a fairer clue. “To be electrocuted” led me to think of “fried” for too long.

Finally, I have never known mud to be called slob.