Dungeons & Dimensions

This mod features many different kinds of dimensions, structures, ore, armor, weapons, and more. 

Fight different kinds of bosses and mobs! Dungeons & Dimensions adds all kinds of mobs most from different dimensions and adds many ores that can be found in the overworld and even other dimensions included in the mod, giving you the chance to explore the dangers of Minecraft and its mysterious creatures! 

More info on the mod in the Wiki.

This mod also needs GeckoLib to work so here's the link: https://www.curseforge.com/minecraft/mc-mods/geckolib