<h2>First Priority Threats</h2>
<p><i>These are pokemon that have the ability to damage your team a lot, and are very hard to counter.</i></p>
<ul>
<li><h3>Curselax</h3>: Once cursed up, it has high stats for everything. You need a true counter for this. Depending on Skarmory to roar away won't help. At the end, when its the last poke, it will own people with only Skarmory as their Snorlax counter</li>
<li><h3>Salamence</h3>: All four moves from a CBMence can hit everything very hard with prediction. DDMence can mess you up if you were expecting a CBMence.</li>
<li><h3>Heracross</h3>: A Pain. Megahorn will do a lot to almost everything not including moltres/skarmory. Rock Slide beats heck out of flyers, Facade can take away lots of Weezing's health and Focus punch will HURT Skarmory.</li>
<li><h3>CB Slaking/Tauros/Dodrio</h3>: If predicted right and used with Magneton, you are OWNED.</li>
<li><h3>Metagross</h3>: Choice Banded or not, this thing will hit everything hard with Meteor Mash and EQ, not including the Metagross counters, although CBgross still does a lot with Meteor Mash to incoming waters/Zapdos. The Skarmory and Weezing get owned by Special Metagross, ie Psychic and Hp Fire/Thunderpunch.</li>
<li><h3>Tyranitar</h3>: Only Swampert can handle both the DDtar and Boahtar, and I heard low defense swampert will die to DDtar. Boahtar and DDtar are some things even a good team can't handle well.</li>
<li><h3>Gengar</h3>: There is no true counter to Gengar. Gengar has the ability to hit ANY pokemon hard, when given the respective moveset. Its attacking moves consist of Thunderbolt, Ice Punch, Fire Punch, Shadow Ball, Focus Punch, Giga Drain/HP Grass, Sludge Bomb and Psychic. I still think I've missed out something. That movepool can SE EVERYTHING, and it works great with Gengar's high sp.atk. Attack isnt really a problem for gengar, its physical moves get stab, except for focus punch, which has a base of 150. Enough to do ~50% to blissey/Snorlax.</li>
<li><h3>Spikes</h3>: 3 rounds of spikes does 25% each time a pokemon switches, and switching is so common in battles. Rapid spin and you can be stopped by a ghost.</li>
</ul>
<h2>Second Priority Threats</h2>
<p><i>These pokemon are easier to counter than members of the first priority threats, but they can pose a problems most of the pokemon here can defeat their counters in some way.</i></p>
<ul>
<li><h3>Suicune</h3>: The old calmcune. With Spikes, this thing can own many. High defense and HP with boosted special = one GREAT tank. Common spinners get hit by surf. Water types get roared away. Blissey cannot outstall a pokemon pressure. Snorlax as a Calmcune counter or water absorbers like Mantine can stop suicune. Venusaur can be used but its risky.</li>
<li><h3>Celebi</h3>: This thing has a WIDE movepool, and like Gengar and Heracross, is very hard to counter. However not many people use sets that truly exploit celebi's uberness, so it is a 2nd priority threat. Salamence switch ins will get worn out by Psychic and some leech seeding. Same for anything that switches in. Metagross is hurt by leech seed, and exploding metagross on celebi could leave you prone to things like CBers using normal attacks. Celebi has higher speed base than houndoom and can BP Calm Minds/Swords Dances out immediately. Dugtrio's HP Bug, even Adamant, cannot ohko a 300 defense Celebi. Phazers get hit by a hard psychic from a CM or 2, and for Swords Dance versions, get hit by a Shadow Ball. And there is much more.</li>
<li><h3>Jirachi</h3>: A pain to battle with, but it is counterable. 101 HP Subs, Wish, Calm Mind together with Psychic and Thunderbolt/Thunder and maybe even Fire Punch/Ice Punch. It has the same typing as Metagross, and has many resistances. The Psychic Sp.def down and electric move Paralysing is extremely annoying. And blissey cannot beat it, snorlax too, unless it has Earthquake.</li>
<li><h3>Swampert</h3>: Cursepert is the main issue here. STAB EQ Hurts everything except flyers/grasses. Roar it away and it will come back for you at the end of the battle. Hitting it with a Grass attack on the rest is probably the best way to counter Swampert. Luckily Swampert will carry only one other attack other than EQ, which something resistant to both attacks would come to haunt Swampert.</li>
<li><h3>Aerodactyl</h3>: Aerodactyl is a Choice Bander, and with prediction, like the other CBers, can hit everything decently. Skarmory dies to Aerodactyl's Rock Slide easily.</li>
<li><h3>Alakazam</h3>: Alakazam uses its powerful sp.atk to kill. Recover Zam beats Ice Beam Blissey and Sub/Encore could annoy Twave blissey while Alakazam sets up. (And snorlax could get beaten by the Focus Punch Trickzam lol)</li>
<li><h3>Zapdos</h3>: Zapdos has awesome special attack and Thunder Wave. Add that together, and zapdos can take down snorlax with a series of Full Paralyses and Thunderbolts. It could make snorlax rest, and make snorlax prone to attacks while resting. Blissey has no problems with Zapdos though.</li>
<li><h3>Raikou</h3>: The classic Fluffy can set up against many things, and if Snorlax is Paralysed or Sleeping, it should watch out. Raikou can destroy Snorlax the same way as Zapdos.</li>
<li><h3>Dugtrio</h3>: You better watch out if any of your pokemon is weak to dugtrio. Once your pokemon is gone, Opponents that should have been countered by the dead pokemon would dominate you.</li>
<li><h3>Gyarados</h3>: Not like Dragon Dance Salamence, which everybody uses Ice Beam to counter. Gyarados needs a different counter, having high sp.def and resistance to Surf and little damage from Ice Beam. Gyarados can easily switch into waters and set up.</li>
<li><h3>Blaziken</h3>: Sky Uppercut, Focus Punch, Rock Slide, Overheat. Who knows, one might just pop up and own you. Blaziken catches switches into Water types with Focus Punch. Its awesome attack will do great with Sky Uppercut. You have to watch out when facing blaziken.</li>
<li><h3>Ninjask</h3>: This thing is commonly seen is noob teams, but it can actually do something that can screw up your team. Ninjask->Exploud is something you should know about. If Ninjask BPs on the first turn and Skarmory just comes in to roar, Ninjask BPs to Magneton, which owned Skarmory without leaving even a round of spikes. And Ninjask will continue to do its BPing...</li>
<li><h3>Medicham</h3>: This thing hits like heracross, except that people don't use it as often as heracross. It has some weezing problems unless it uses return/psychic.</li>
<li><h3>Flygon</h3>: Another Choice Bander. Again, not everybody has a grass type and everybody probably has only something or two resistant to EQ. If Flygon predicts with Rock Slide and kills your flyer, prepare to get swept by EQ.</li>
</ul>
<h2>Third Priority Threats</h2>
<p><i>These don't really post a threat to many teams, but they can when used well and you should also watch out for them.</i></p>
<ul>
<li><h3>Milotic</h3>: A common Water type currently. Reason: It has hypnosis. So it can go hypnotise your Snorlax and start switching to something like Raikou to own you.</li>
<li><h3>Moltres</h3>: Sunny Dayed STAB Fire Blast OHKOs Regice. Moltres has the strongest Fire Attack and Fire is an awesome offensive type while flying helps it more by resisting Earthquake.</li>
<li><h3>Jolteon</h3>: Jolteon can BP Substitutes like ie BPing Sub to Gengar when Snorlax tries to Body Slam it. Watch out for that sometimes.</li>
<li><h3>Breloom</h3>: For some teams, Breloom can be a threat because of the common use of rest. Resting pokemon give Breloom a nice chance to Focus punch.</li>
<li><h3>Status Conditions</h3>: You definitely do not want Salamence to be burnt and Gengar to be thunderwaved.</li>
<li><h3>Dragonite</h3>: Dragonite has a great movepool. Its awesome attack allows it to use Salamence's moves, while it has 100 base special attack and Thunderbolt to take down waters that come in to Ice Beam Dragonite.</li>
<li><h3>Marowak</h3>: Thick Club gives it Uber Attack. EQ/DE/RS hits everything hard, while Focus Punch will Hurt Skarmory which has no choice but to roar a SDed Marowak away.</li>
<li><h3>Rhydon</h3>: CB Rhydon does a lot to many pokemon with the combo RS/EQ/Megahorn. Skarmory will take a beating from Focus Punch Rhydon. Switching Water types into a STAB Earthquake is not what you will like.</li>
<li><h3>Starmie/Lanturn/Lapras</h3>: Especially Starmie, these three pokemon cannot be countered by just simple water types etc. They need a special tank to take all of their hits. Boltbeam makes them hard to counter using non-special tanks.</li>
</ul>
<h2>Fourth Priority Threats</h2>
<p><i>UU Pokemon that can do well against some OU teams.</p>
<ul>
<li><h3>UU CBers</h3>: Again, with prediction, CBers can hit things well.</li>
<li><h3>Mr. Mime</h3>: It has soundproof. And Calm Mind with baton pass and Trick/Torment too. And Thunderbolt/Psychic to beat down Skarm/Suicune/Weezing. Commonly seen in pure BP teams.</li>
<li><h3>Slowbro</h3>: A water type with amazing defense and Calm Mind to raise its already high special. Beats blissey 1 on 1.</li>
<li><h3>Tentacruel</h3>: An exceptionally good UU pokemon that uses Swords Danced Sludge Bomb + Hydro Pump to sweep. This combo again has very few resistances and can potentially sweep OU teams. 2 STABed attacks running of a boosted attack and an already high special attck are deadly.</li>
<li><h3>Ursaring</h3>: Resttalk boosts its Guts. Combined with high base Atk, Swords Dance and STAB Return, this thing will do >50% to skarmory with a SDed Return.</li>
<li><h3>Entei</h3>: 101 HP subs, Calm Mind, very fast and has decent special attack. Beats blissey one on one.</li>
</ul>
<h2>Indirect Threats</h2>
<p><i>These do not pose a threat by themselves, but they can help make a threat even more powerful.</i></p>
<ul>
<li><h3>Mr. Mime</h3>: It has soundproof. And Calm Mind with baton pass and Trick/Torment too. And Thunderbolt/Psychic to beat down Skarm/Suicune/Weezing. Commonly seen in pure BP teams.</li>
<li><h3>Mawile/Absol</h3>: Swords Dance, Taunt Phazers and Baton Pass. The recepient will proceed to kill the phazer with whatever it has.</li>
<li><h3>Heal bell/Aromatherapy/Wish</h3>: Basically, these are team support moves. They help things like Salamence to survive and own your team.</li>
<li><h3>Leech Seed</h3>: Helps wear down the opponent's team over time, helps in stalling in conjunction with substitute and helps heal weaker pokemon in your team.</li>
<li><h3>Celebi</h3>: Celebi can also be an indirect threat by passing Calm Minds and Swords Dances extremely well.</li>
<li><h3>Umbreon</h3>: Tauntbreon is a pain. It traps and stops phazers, then proceeds to BP to a counter.</li>
</ul>
<h2>Threats to Specific Pokemon</h2>
<p><i>Pokemon meant to hurt some specific pokemon but generally dont pose a very big threat to other pokes</i></p>
<ul>
<li><h3>Magneton -> Skarmory</h3> : Traps Skarmory with Magnet Pull</li>
<li><h3>Dugtrio -> Heracross/Metagross etc.</h3> : Mainly used to kill these pokemon but duggy also servers the purpose of finishing off many pokemon that are low in health.</li>
<li><h3>Houndoom -> Gengar/Weezing/Alakazam/Celebi(kinda)</h3> : This pokemon has awesome speed and special attacks and STABed pursuit which helps it hit all these pokemon when they switch out. It also gets excellent STAB attacks to deal good damage</li>
</ul>
<br>
<small>Acknowledgements: vapicuno, Assman</small>