KO a Character: Pokémon

Ekans
Arbok
Raichu
Sandshrew
Sandslash
Nidorina
Nidoqueen
Nidoran (m)
Nidorino
Nidoking
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Eevee
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
Eliminating Sandshrew because I find its Kantonian variant too common (although the Alolan one is all right).
Ekans
Arbok
Raichu
Sandshrew
Sandslash
Nidorina
Nidoqueen
Nidoran (m)
Nidorino
Nidoking
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
I've already started but will continue on the Nido line as there are still Pokemon that interest me more in Gen I, with Tentacruel probably being my favorite left on this list for Gen I for it being a Water/Poison type that can learn Ice moves that are useful against Lance, and a cool, threatening design. So even though Tentacool is a common Pokemon it evolves into a good Pokemon that's very useful too.
Ekans
Arbok
Raichu
Sandslash
Nidorina
Nidoqueen
Nidoran (m)
Nidorino
Nidoking
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
Ekans
Arbok
Raichu
Sandslash
Nidorina
Nidoqueen
Nidorino
Nidoking
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
The Nido designs just don't interest me like they should
Ekans
Arbok
Raichu
Sandslash
Nidoqueen
Nidorino
Nidoking
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
Ekans
Arbok
Raichu
Sandslash
Nidoqueen
Nidoking
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
Ekans
Arbok
Raichu
Sandslash
Nidoqueen
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
Ekans
Arbok
Raichu
Sandslash
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew
 
Both Doduo and Dodrio are examples of Pokémon designs that while not awful just don't quite appeal to me as much as they should (this will be my last time saying this for a while as this is the reason for why I will eliminate many more Gen I Pokémon)
Arbok
Raichu
Sandslash
Clefairy
Clefable
Vulpix
Ninetales
Vileplume
Venonat
Venomoth
Meowth
Persian
Psyduck
Golduck
Primeape
Growlithe
Arcanine
Kadabra
Alakazam
Tentacool
Tentacruel
Ponyta
Rapidash
Slowpoke
Slowbro
Magnemite
Magneton
Doduo
Dodrio
Seel
Dewgong
Shellder
Cloyster
Haunter
Gengar
Onix
Krabby
Kingler
Exeggutor
Cubone
Marowak
Hitmonlee
Hitmonchan
Rhyhorn
Rhydon
Chansey
Tangela
Kangaskhan
Seadra
Scyther
Electabuzz
Magmar
Pinsir
Tauros
Gyarados
Lapras
Vaporeon
Jolteon
Flareon
Omantyte
Omastar
Kabuto
Kabutops
Aerodactyl
Articuno
Zapdos
Moltres
Dratini
Dragonite
Mew