Virtual Elements Method, unlike FEM, works with any kind of grid elements, from regular to non-regular shapes. Since it is a research field, there are not many resources and experimental grids need to be created to test this new algorithm. This method can be used to mesh very rough surfaces (like a rock with many irregular spikes and holes) and, from initial tests, faster than FEM on solving systems of partial differential equations.

List of Matlab scripts that generates polygonal (regular and irregular) grids with particular requirements to be used in VEM solvers.

I have created a simple online platform to build custom shape to be arrange into a grid. You can then export the new shapes in a CSV file for further manipulation. In the matlab folder in the following repo you can find a script that takes as input the CSV shape and outputs a NxM grid.
createGrid() repo

Hexagons Explanation
Pentagonal Tilings
An Introduction to Virtual Elements Method
Matlab Documentation
Mesh Refinement