I created a fully procedural alien egg material with Substance Designer with an extraordinary approach. First I created one side of the egg and used a "shape mapper node" to tile the texture in a spherical style by 4 to use on my simple semispheric UVed egg mesh.
It fit good to use on my previous procedural Derelict Spaceship Wall material.
https://www.artstation.com/artwork/GR211
Hope you like it.
Cheers!