The 'In Common' Game

[vaporeon7]

The only thing I can think of is they both have a x4 weakness to Bug.
What about
Gorebyss

and
Seel?

Hint:

Spoiler:

The Pokedex.

 

[DoctorFred]

Seel is 178 in the Johto pokedex and Gorebyss in 178 in the Hoenn pokedex?

What about Porygon and Mewtwo? (this one is quite easy if you ask me)

 

[vaporeon7]

Both were created by humans.
What about...
Girafarig

and
Eevee?

 

[Eliminator Jr.]

Both names are spelled the same backwards. What's similar between Scizor and Magmortar?

 

[dragonite149]

They both evolve from Pokemon introduced in Gen 1!
Pinsir and Koffing?
Hint:

Spoiler:

They're spinning off the beaten path, not following the signposts.

The hint is like a short riddle.

 

[wayne111222333444555]

They're both introduced in Gen 1?
That's the only one I have in mind...
How about
Denchura and Chatot?

Spoiler:

You could only find the answer, if you check out their numbers...

 

[vaporeon7]

Chatot's Sinnoh Pokedex number is 102 and Denchura's Unova Pokedex number is also 102.
What about
Vaporeon

and
Relicanth

Hint:

Spoiler:

They share something at the same level.

 

[Meduza]

They both learn Hydro Pump at Level 71.

What do Koffing and Gloom have in common?

Hint: You'll have use your sniffer for this question.

 

[Hoppip]

They both smell.
How about Hoppip and Nidoran (male)?
Hint:

Spoiler:

It may confuse you.

 

[vaporeon7]

They both learn Confusion through breeding.
What about...
Skitty

and
Choroneko?

Hint:

Spoiler:

I'm rich, rich I tell you!

 

[DoctorFred]

According to your hint, it would be that, they both learn Pay Day. Choroneko learns it via breeding, and Skitty learns it via Pokemon Box Ruby and Sapphire if you have 500 pokemon.

What about: Unown and Magnemite?

Spoiler:

Just look at them.

 

[Hoppip]

They both have one eye.
How about Jumpluff and Froslass?
Hint:

Spoiler:

Wouldn't really need Chlorophyll.

 

[vaporeon7]

They both have a 110 base speed stat.
What about...
Sunkern

and
Mew?

Hint:

Spoiler:

They both have the best possible.

 

[Hoppip]

They both can have a maximum Pokeathlon Stats.
What about Igglybuff and Nidoran (f)?

Spoiler:

Cleffa and Nidoran (m) as well.

 

[dragonite149]

They both have the same Attack/Defense/Speed/HP/SpAttack/SpDefense?

@Wayne
The correct answer was in Pokemon Snap, a spin-off game, they were both Pokemon Signs. But, you are right~

Try...
Trapinch and Kirlia.

Hinty-hint:

Spoiler:

You gotta boogie if you wanna know the answer!

 

[Arma]

Those animated dancing gifs??

Let's see

Zangoose & staraptor.

Spoiler:

it also decreases their already low defenses.

 

[vaporeon7]

They both learn Close Combat.
What about
Spinda

and
Glalie?

Hint:

Spoiler:

Both of them don't vary in something.

 

[DNZGames]

They both have the same Base Happiness?
They both don't vary in Male/Female ratio?

What about:
Luvdisc & Stantler

 

[Arma]

They both have the same Base Happiness?
They both don't vary in Male/Female ratio?

Al they're stats are the same (60 for Spinda and 80 for Glalie)

What about:
Luvdisc & Stantler

They're both useless, they both can't evolve. Some Gen V Pokemon were introduced that bear a striking resemblance to them.

What about Marakacchi and Erufuun?
Hint:

Spoiler:

They're The only pured typed ones of they're types who can't learn it.

 

[FlamingThunder]

They can't use Razor Leaf via leveling up?


How about:

Electabuzz and Magmar?

HINT:

Spoiler:

It has something to do with evolution at Gen. II and Gen.IV