Odd One Out (minus the double posts!)

[KetsuekiR]

Porygon Z is the only one not available in Johto and Hoenn!

Magnezone, Lucario and Bronzong?

 

[Corrin]

Lucario is the one with a mega evo

Goodra, Noivern, Draglage?

 

[Zoroark Cutie]

Goodra is the only one who is a mono-type.

Delibird, Darmanitan, and Aegislash

 

[Ace Trainer 188]

Delibird is the only non evolver.

Paras, Grimer, Graveler

 

[Corrin]

Graveler has evolved

Mareep, Geodude, Shinx

 

[Ace Trainer 188]

Geodude isn't an electric mon!

Metapod, Kadabra, Bayleef.

 

[Corrin]

Kadabra evolves through trade

Reuniclus, Gothitelle, Archeops

 

[nxwing]

Archeops - Pre-evolution you can only get through fossil

Raichu, Luxray, Magnezone

 

[Ace Trainer 188]

Magnezone is the only one who is dual typed.

Typhlosion, Machamp, Golem

 

[Corrin]

Typhlosion doesn't evolve via trade

Sceptile, Blaziken, Swampert

 

[Zoroark Cutie]

Blaziken is the only one to get its mega before OR/AS.

Teddiursa, Zigzagoon, and Minccino

 

[Ace Trainer 188]

Zigzagoon is a first router, but the other 2 aren't.

Blaziken, Politoed, Walrein.

 

[Corrin]

Politoed is an alternate evo

Ghastly, Haunter, Gengar

 

[Zoroark Cutie]

Ghastly is the only one who doesn't have a vowel as the 2nd letter in its name.

Fearow, Drifblim, and Noivern

 

[Ace Trainer 188]

Fearow was introduced in an odd numbered gen, unlike the others.

Abra, Metapod, Ditto!

 

[Corrin]

Ditto doesn't evolve

Mewtwo, Mew, Jirachi

 

[Ace Trainer 188]

Jirachi is dual typed.

Mons who got evos in later gens:
Magneton, Piloswine, Porygon2.

 

[Zoroark Cutie]

Piloswine is the only who wasn't originally from Gen 1.

Bayleaf, Groovyle, and Serperior

 

[Lycanthropy]

Serperior is the only one without feet.

Zubat, Woobat, Noibat

 

[Poké Bean]

Noibat cuz it doesn't have any top teeth!

Meowth, Purrloin, Espurr