>>61039
>First big green Ogre
The Ogre in MGE is just your bog standard Oni, whereas the Ao and Aka Oni are both references to Naita Aka Oni or the story of Momotaro, and are a common pairing in Japanese folklore.
>Hellhound
Hounds as the guardians of the Underworld go as far back as the Greeks and Romans with Cerberus as the hound of Hades/Pluto, or Garmr from Germanic folklore. The specific design in MGE is influenced ( at least IMO ) by the British Barghest, Black Shuck, and even the Bayeux hound.
>Angels
So, Angels obviously come from Judeo-Christian origins but up until cultural osmosis during post-Hellenistic Greece and even the Renaissance they were never depicted entirely as just humans with wings. They used to have more esoteric forms like the Byzantine Cherubim or looked like normal people. It wasn't until the ministry of the Apostle Paul and later that they would become associated with figures like the Goddess of Victory, Nike or Eros Aphroditus, the God of Erotic Love. Both of whom embodied the beauty of the human form and more times than not had wings.
Coincidentally, Valkyrie being depicted with wings is also a cultural whitewashing of them after Christianity spread to pagan Scandinavia.
>Bicorn
Literally popularized by Chaucer after he got word of them from the French. They were a satirical commentary about sexuality in France, and later spread around Europe, to show that to have a good wife meant you had one as rare as a Unicorn. Ironically, it didn't really start getting depicted as a goat or dual horned Unicorn type creature until games like Megami Tensei popularized the image. Before hand it was just simply a fatass creature not dissimilar to a hippopotamus.