Notes:

Quick observations:

• Vullaby/Mandibuzz doesn't exist in early builds. Same goes for Durant, Bouffalant, Cottonee, Whimsicott, Lilligant, Eelektrik.
• Shelmet was supposed to evolve into Escavalier. Karrablast meanwhile had its own evolution.
• Stunfisk is blue because it was originally Water/Electric.
• In older builds, there was no Zebstrika, but a weird-looking middle stage between the two Zebra mons.
• Early versions of Black and White Kyurem were just a Red and Blue Kyurem.
  *Mons that exist but weren't included in here for some reason:
  • Oshawott's family
  • Venipede and Scolipede
  • Darumaka
  • Darmanitan
  • Axew
  • Fraxure
  • Haxorus