People have been living in Ehtiopia since... well... just about since people have been. Obviously, a place with such a long history of having humans there is going to be full of legends and lore that would make great fodder for your gaming sessions. And that's just what Skirmisher Publishing has done. They've created Men & Monsters of Ehtiopia, a new sourcebook for use with 5th Edition Dungeons & Dragons.
The book has quite a lot going on in it. There are 17 new monsters with 29 stat blocks for them. There's 20 pre-existing monsters that have been adapted for the setting. There's 11 types of NPC, with 5 new stat blocks for them. There's a section on the religions and animals in the region. And to put them all together, encounter tables.