Author: David Necas "Yeti"
In menu: Filters → Render → Pattern → Voronoi...
Technically, Voronoi generates 2D Voronoi diagrams of various semi-random sets of points and then visualizes them somehow.
What are Voronoi diagrams
Imagine a finite set of points in some metric space (or just just normal n-dimensional space, if you don't know much about metric spaces).
If you now take any point of the space, there definitely exists a point of the set which is closest to this point.
This way the set breaks the space to parts, (called cells below) each consisting of points nearest to a one point of the set.
This division is what is called Voronoi diagram of the set (roughly).
Compiled for Gimp-2.10.22 Win_64bit: MareroQ