GamePress
Gen 3 10k eggs speculation.
10k joy mons:
Bagon
Beldum
Feebas
Slakoth
Anorith
Lileep
And Aron
And the 10k mehpokemon you will get:
Sableye
Mawile
Kekleon
And Nosepass
Report
Answers
I don't think Feebas would hatch from 10km eggs, the way I see it Feebas is similar to Magikarp and that they would make it somewhat common but make it so the candy needed to evolve to Milotic would be 400 or something similar to Magikarp->Gyarados evolution. But that's just my thoughts, good list :)