From PokéHeroes Wiki
Retro Pokemon are Pokemon with Gen 1-3 sprites. They are not breedable.
Obtaining Retro Pokémon
Not all the Retro Pokémon are obtainable currently, but some can be obtained by purchasing Premium-ship.
- - Retro Bulbasaur, Retro Charmander and Retro Squirtle can be obtained as vouchers when purchasing Premium membership. (1 voucher per month.)
- - Retro Venusaur, Retro Charizard and Retro Blastoise could be obtained for a limited time in the Retro Radar Game.
- - Retro Rattata, Retro Zubat, Retro Koffing were obtainable from 22/May/2018 to 12/Jun/2018 through the Johto Apricorn Battle. If you unlocked the Burned Tower Rumble Area you can obtain those retro eggs randomly.
- - Retro Pikachu was an event Pokemon obtainable from 22/Jul/2013 to 28/Jul/2013. It was then made obtainable again during the Retro Pikachu Event through the Yellow Forest.
- - Retro Magikarp is currently only once obtainable as a gift from Prof. Rowan for helping him in a quest.
- - Retro Articuno, Retro Zapdos and Retro Moltres could be obtained for a limited time in the Retro Radar Game.
- - Retro Mew can be obtained as a voucher when purchasing 1 year Premium membership.
- - Retro Chikorita, Retro Cyndaquil, Retro Totodile, Retro Sentret and Retro Hoothoot can be obtained as daily rewards from the Concentration Game.
- - Retro Meganium, Retro Typhlosion and Retro Feraligatr could be obtained for a limited time in the Retro Radar Game.
- - Retro Marill was an event Pokemon obtainable from 22/May/2018 to 12/Jun/2018 through the Johto Apricorn Battle. You were able to win one every day if you make Top 50.
- - Retro Togepi can be obtained from the Daycare. After adopting 500 eggs from the daycare, the owner will ask you if you would like to take care of a mysterious egg. You can get another Retro Togepi for every 500 eggs you adopt form the Daycare.
- - Retro Delibird was rarely obtainable through Christmas gifts during the Advent time. [2013 / 2014 / 2015 / 2016 / / 2017]
- - Retro Lugia and Retro Ho-Oh were randomly obtainable as reward during the Speed Click Event in February 2018. They are now obtainable though the Burned Tower Rumble Area if it was unlocked during the Johto Apricorn Battle 22/May/2018 to 12/Jun/2018.
- - Retro Poochyena, Retro Zigzagoon, and Retro Taillow was obtained during 'Month of Hoenn', from 18/01/14 to 31/01/14. It was then made obtainable again during the ORAS Event through the Route 102 Rumble Area.