Added 6 Alien and 3 Mud Textures

Hey all,

Today I added 6 Alien and 3 Mud Textures to the already existing ones. 

I try to upgrade most packages to around 10 Textures. This should lead to a good variety. 

I currently plan some new texture topics for the future, remember if you want or need anything special, let me know and I try to add it in a future update!

If you like it so far, please consider rating the Asset. Thank you!