What are all the Pokemon can you encounter in Horde Battles?

Question

And where can I find them?

Answer 1

• Route 5: Plusle, Minun, Gulpin, Scraggy
• Route 7: Hoppip, Psyduck, Roselia
• Route 8: Wingull, Taillow, Zangoose, Seviper
• Route 10: Yanma, Electrike (Y), Nosepass, Houndour (X)
• Route 11: Starly, Stunky, Nidoran-F, Nidoran-M
• Route 12: Taillow, Tauros, Miltank, Mareep
• Route 14: Bellsprout, Skorupi
• Route 15: Murkrow, Foongus
• Route 16: Murkrow, Foongus
• Route 18: Geodude, Heatmor, Durant
• Route 19: Skorupi, Arbok, Weepinbell, Gligar
• Route 20: Foongus, Sudowoodo, Trevenant
• Route 21: Scyther, Spinda, Swablu
• Pokemon Village: Foongus, Poliwag, Noctowl, Lombre
• Terminus Cave: Geodude, Durant, Aron, Larvitar
• Victory Road: Geodude, Lickitung, Graveler, Floatzel
• Connecting Cave: Whismur, Zubat, Axew
• Reflection Cave: Mime Jr., Carbink, Roggenrola
• Frost Cavern: Smoochum, Bergmite, Cubchoo
• Azure Bay: Slowpoke, Exeggcute

Source