I think that Skarmory, Farfetch'd, Delibird, Heracross, Pinsir, Lapras, Unown, Tropius, Plusle, Minun, and Chatot should get a baby stage.
Skarmory, Farfetch'd, Delibird, and Chatot could have little chicks.
Pinsir and Heracross could be like little larvae and the Pinsir larvae could have a large jaw.
Tropius could have a cute little smaller version of itself without fruit and leaves so small, it's not part Flying-type yet.
Plusle and minun can have a baby evolution without a charge called 'Neutralon' or something...