ExtraResources

ExtraResources is a mod that takes what Minecraft already has and builds upon it. This mod contains new materials to use for various purposes, and has new mobs, a new biomes, new crafting stations, new structures, and new bosses in order to utilize these materials. You'll also have to explore many of the vanilla biomes in order to gather these resources,

This mod is also constantly changing as well. Found a bug? Think something should be changed? Let me know in the comments, and I'll try to fix/change the thing you commented on. I'm going to try to constantly tweak and fix things until they are how they should be.

Trying to beat the mod? Good luck, you'll need it, especially because this mod is pretty difficult, especially in the early game.

NOTES: This mod changes the value of vanilla items. For example, diamonds are much easier to obtain, so diamond would have less value. This mod isn't particularly great for modpacks because of these vanilla item value changes.

Good luck, and have fun! 

If you enjoyed the mod, or had an issue with the mod that you want to address, please consider leaving a review here: https://mmcreviews.com/all/mods/extraresources/ 
This is important so that I know what to focus on, whether that be to add new content or bugfixing or revamping old things that need to be redone.