Common flaapy eggs: Charmander, Cleffa, Diglett, Electrike, Geodude, Hoothoot, Ledyba, Machop, Magikarp, Mareep, Marill, Nidoran (both), Oddish, Phanpy, Pidgey, Poochyena, Rattata, Sentret, Slugma, Spinarak, Sunkern, Swinub, Treecko, Zigzagoon, Zubat.
I also acquired a shiny Electrike from a common flaapy egg.