Dremora - Just about always servants of Mehrunes Dagon in all their forms
Xivilai - The same as Dremora just "wilder"
Golden Saints / Aureals - Only known to serve Sheogorath?
Dark Seducers / Mazken- Have been known to serve Sheogorath and Mehrunes Dagon
Knights of Order - Serve only Jyggalag
Aurorans - Serve only Meridia (and Umaril)?
Daedroth - Serve Molag Bal, but seen in the ranks of Mehrunes' army...
Clannfear - Serve multiple masters
Flame, Frost, Storm Atronachs - have no master
Steel Atronach - ?
Flesh Atronach - created by the sorceress Relmyna Verenim and used as hosts for Daedra spirits by Sheogorath, right?
Winged Twilight - only serve Azura? Molag Bal's "daughter" is one...
Spider Daedra - serve Mephala, but seen in the ranks of Mehrunes' army...
Ogrim - only serve Malacath?
Hungers - serve Boethiah but for some reason they appear in Sheogorath's (his enemy) realm and the Madgod calls them one of his favorite pets...
Scamps - only serve Mehrunes Dagon?
Vermai - only serve Mehrunes Dagon?
Morphoid - only serve Mehrunes Dagon?
Herne - Mehrunes Dagon and Hircine
Daedra Seducers - I am utterly confused by them, are they not Dark Seducers but just with wings? what?
Skinned Hound / Bonewolf - Seen in the Shivering Isles and Morrowind but no other clue about them really. Are they just undead?
Shambles - Seen in the Shivering Isles but no other clue about them really. Are they just undead/constructs?
Hell Hound - maybe the Skinned Hound / Bonewolf before necrotization? (from Arena)
Homonculus - a botched (or purposefully botched) conjuration of different daedra to form something all different parts of nasty? (from Arena)
Baliwog/Grummites - Are these daedra? They live in Shivering Isles. Found nowhere else.
Elytra - Are these daedra? They live in Shivering Isles. Found nowhere else.
Gnarl - Are these daedra? They live in Shivering Isles. Found nowhere else.
Scalon - Are these daedra? They live in Shivering Isles. Found nowhere else.
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Obviously adding more Aurorans, Dark Seducers, Golden Saints, Hungers, Skinned Hound/Bonewolves and some others to the game will be easy as they are already present in the Shivering Isles and Knights of the Nine.
Hell Hound would be easy to make using current wolves from Oblivion just "beefed up" in the mesh a bit and adding flames to their mouths
I am currently working on a mesh for Winged Twilight just waiting for it to be rigged to a skeleton I modded.
I saw someone making a Vermai once on Youtube here: http://www.youtube.com/watch?v=_2nIwwmF81Y (extremely well done mesh and animations) but never saw anything else of it.
Anyways, I'm going to be adding some more Daedric shrine ruins around Cyrodiil like were present in Morrowind and Daggerfall and also will be allowing Conjurer dens to have these present as well; mixed in.