These look like some kind of alien pods. I’m not sure if they are alive or not!
Rundel is an interesting tangle. It’s self-contained, shaped a bit like Purk, and doesn’t look all that good when you first draw it. As you can see above, with some additional decoration and shading, it really looks much more interesting.
Zentangle drawn on Strathmore Vellum Bristol using a black, Micron pen.