Just for reference purposes, we see the following Good creatures in D&D:
MM:
Blink dog, celestials, centaur, couatl, dragons (metallic), dryad, dwarf, elf, genie (djinn), giant (cloud and storm), giant eagle, giant owl, gnome, halfling (well, traditionally at least), lammasu, lillend, naga (guardian), nymph, pegasus, planetouched (aasimar), pseudodragon, sphinx (androsphinx), sprite (grig, pixie), titan, treant, triton, unicorn (also, the celestial, half-celestial, half-dragon, and werebear templates can create good creatures)
Monsters of Faerun:
Aarakocra, dragon (song), hybsil
Manual of the Planes:
Bariaur
Oriental Adventures:
Hengeyokai, ki-rin, korobokuru, nat (einsaung), shirokinukatsukami, spirit folk
Monster Manual II:
Asperi, desmodu, felldrakes, giant (ocean), phoenix (also, the tauric, and monster of legend templates can create good creatures)
Tome of Horrors:
Brownie, dragon (fairie), dragon horse, flumpg, giant (wood), hippocampus, moon dog, shedu (also, the abomination and foo creatures templates can create good creatures)
Creature Catalog:
Air sentinel, anuchu, baku, beastman, caiveh, dobie, dragon (adamantite, mercury), faerie fiddler, frost, grim, halfling (wild), hollyphant, monkey spider, moon-horse, opinicus, selkie, swanmay, uldra
And I’m sure there are others - notice that good creatures are a lot harder to find in D&D than neutral or evil ones.
Not that your entry needs to be of "automatic" good alignment; note that I do like the half-orc idea above a lot! If you can come up with a good enough reason why a beholder or red dragon would make a good celestial lord, I'll tell ya what I think about that!
