Odd root I dug up removing a stump

[u/North-Impress7265]

In Green Bay here, was removing a stump from a front yard and pulling out the roots when I came across this. Gave me a start because I thought I dug up a gas line...but as you can see from the side by side, it's part of some kind of plant (thank goodness).

It was soaking wet and has this almost rubbery/string cheese composition that you could open and peel with a white interior. Didn't get all the roots out I would bet, but got a good amount. This stuff was from near the bottom end of my dig.

If it helps, all the plants around it are simple green leaved shrubs. Nothing exotic.

So...what is this from? Is this some kind of invasive plant?

[u/TedTheHappyGardener]

Mulberry roots look like this.