Worst mistake to ever make in the Pokémon world...

[Jetz]

Worst Mistakes To Do
If You get in a fight with slaking
Drawing A GROUDON ON THE SAND with a meteorite and jirachi
If You PICK SNIVY

[Mondo Oowada]

Picking Chikorita, any of the Sinnoh starters (except Chimchar), or Snivy as a starter Pokemon. I hate all of those.

[OranBerrySandvich]

Introduce legendaries to alcohol.
The last thing we need is Regirock punching Celebi in the eye.

[Mondo Oowada]

Introducing Ash to sugar without appropriate protection.
APPROPRIATE: Machete, SMG, fast transportation. Also, some sort of sedative.
INAPPROPRIATE: Cheese sandwich, more sugar, plush toy. Also, a pen.

[Captain Jigglypuff]

Going on a date with Brock who probably would drug you!
Being called "Team [Insert Name]
Being a Snover during the Christmas season
Kissing a Jynx if you are white!

[Nightmare Eater]

Being a Snover during the Christmas season
Kissing a Jynx if you are white!

I see no problem being a Snover. And the last one, really?

[Captain Jigglypuff]

I see no problem being a Snover. And the last one, really?

Snover because people would try to chop you down only for you to die and wither into nothing until the end of March when the people who basically killed you decides to throw you away and the Jynx one is in reference to the banned Ice Cave episode!

[Captain Jigglypuff]

Snuggling a Cacnea or Cacturne would be bad!

[Mondo Oowada]

Double posting is bad.
So is making your Slowpoke forget Amnesia. Watch and learn.

Poor move deleter man.

[RioluRiku]

pics or vid, why?  try yourselves it's easy to beat him  , with his team in lv.50 some revive and smart thinking.
i didn't take a pic or vid because i thoght since i did it everybody can do it 

easy means no 0-2 pokemon lost and no revives/healing items...

well thats the way i see it.

[Mondo Oowada]

When an opponent uses Stealth Rock, never send out Volcarona.

[Reshurott Inferno]

Probably Emboar. Slow, lack of access to a Dark-type move that has above 50 BP, bad defenses, etc.
At least, to me.

[Legacy]

Don't ever agree to sleep in the same room as a Snorlax.
Don't leave your dinner on the table with a Munchlax around.
Don't hug a Cacnea/Cacturne/Maractus.

[Sappy]

Catching a wild Metapod. :3

[Legacy]

Or a wild Kakuna <.< hehe