This is a collaboration with Charan from Just 3D Things.
Procedural Moss is a node group designed for the Cycles rendering engine that will let you generate moss effects around an object.
Note: Procedural Moss is intended to be used in combination with adaptive subdivision, meaning that it is performance-heavy and will require a significant amount of VRAM for high-poly meshes.
This node group will also work with EEVEE, however you will need to unplug the displacement output.
You can combine your own texture maps with the node to make sure the moss is generated over the top of the original surface.