Although Poison as a type fell off as many of the more influential Mega Evolutions, notably Mega Diancie and Mega Gallade, were released, as the metagame balanced out Poison has reestablished itself as a sturdy defensive type capable of taking on dominant types such as Flying, Fairy, and Water while matching up decently with the rest of the metagame. With huge upgrades it has received as a type since ORAS, Poison differentiates itself from the shadow it was back then. Let's take a look at Poison-type teams and how they function in the SM Monotype metagame.
Defensive Pokémon
Mega Venusaur
Mega Venusaur's wonderful bulk and good defensive typing are what make it a staple on each and every Poison team. It contributes to the defensive core, along with Toxapex and Alolan Muk, with its huge defenses and good defensive typing, along with reliable recovery in Synthesis. Mega Venusaur's Grass typing grants it valuable resistances to Electric and Water while giving it a Ground neutrality, therefore allowing it to reliably switch into threats such as Tapu Koko, Choice Scarf Excadrill, and Mega Swampert for the rest of the Poison team. It is also Poison's only defensive check to Azumarill, as it Speed creeps and knocks it out with a strong Sludge Bomb even after it uses Belly Drum.
Toxapex
Toxapex is one of the most dominant defensive threats in Monotype and an important member of Poison's defensive core. With extremely good bulk, a good defensive typing in Water, reliable recovery in Recover, a spectacular defensive ability in Regenerator, and access to Toxic Spikes, Toxapex is an extremely valuable member of Poison teams. Toxapex's Water typing provides the team with a sturdy Fire-, Ice-, and Steel-type answer. It's also able to check prominent metagame threats such as Mega Scizor, Mega Lopunny, Mega Charizard Y, and much more Pokémon with its defensive typing in conjunction with its bulk while also checking setup sweepers with Haze. Toxapex's defensive traits also allow it to be an extremely effective Toxic Spikes setter, which consistently helps in matchups such as Fairy, Normal, Psychic, and Ground by wearing the opposing team down. Baneful Bunker also allows it to scout attacks and is very effective against Normal teams in conjunction with Toxic Spikes. With all this being said, Toxapex is definitely a staple on Poison teams right now and will remain so in the near future.
Alolan Muk
One may wonder how Poison teams thrive with Psychic coverage in the metagame. That's where Alolan Muk, the last member of the defensive core, comes in. Alolan Muk's ability to switch into Psychic-type attacks for the rest of the team makes it a must-have on every Poison team. With its Dark typing and respectable special bulk along with Assault Vest, Alolan Muk is able to switch into Psychic-type Pokémon such as Latios, Alolan Raichu, and offensive Mew and trap and remove them with Pursuit. It can also use Knock Off to soften up opposing teams by removing various items such as Eviolite, Leftovers, and Choice items. However, despite its good special bulk, its physical bulk is considerably lower, and Alolan Muk has no form of reliable recovery while holding an Assault Vest. Therefore, it has to be kept healthy throughout a match in order for it to consistently switch into, trap, and remove Psychic-type Pokémon. An alternative set with Recycle and Figy Berry can be used to solve the recovery issue, although this limits Alolan Muk's ability to switch into powerful special attacks.
Crobat
Crobat provides irreplaceable defensive utility for Poison teams through Defog and a reliable Ground immunity. Defog is important because it prevents Crobat's teammates from quickly getting worn down through continuously switching into layers of Spikes or Stealth Rock, and having an immunity to Ground-type attacks is crucial because it allows Crobat to switch into strong attacks such as Excadrill's Earthquake and Landorus's Earth Power for the rest of the team. Crobat's naturally high Speed allows it to check huge threats such as Mega Pinsir and Mega Gallade, both which can tear through Poison teams after a Swords Dance. Black Sludge provides Crobat with passive recovery, Rocky Helmet can be used on Crobat to spread chip damage, and Flyinium Z is another option that provides a nuke in Z-Brave Bird.
Salazzle
Salazzle's role on Poison-type teams comes from its ability to use Substitute in conjunction with Toxic to wear opposing Pokémon down. Its ability Corrosion plays a huge role in this, as it allows Salazzle to poison Poison- and Steel-type Pokémon such as Toxapex, Mega Venusaur, Heatran, and Celesteela, therefore wearing them down for its other teammates to take advantage of. However, Salazzle's bulk is rather lackluster, which means that it has to rely on its huge Speed stat to spam Substitute and Toxic, as it cannot afford to be hit by a strong attack or get chipped due to Leftovers being its only form of recovery. Its Stealth Rock weakness also hinders this role, as it limits the number of times Salazzle can effectively switch in if entry hazards are not removed by Crobat's Defog.
Offensive Pokémon
Nihilego
Nihilego comes into play on Poison as its main Choice Scarf user that is capable revenge killing Pokémon such as Garchomp and threatening types such as Fire and Flying with its coverage. Furthermore, access to Stealth Rock make it one of the primary Stealth Rock setters on the type. It is also able to compress the roles of Choice Scarf user and Stealth Rock setter, freeing up moveslots on other Pokémon, which is especially good for Poison-type teams, since they usually are limited to two flexible teamslots outside of the usual defensive core.
Nidoking
Nidoking's vast coverage along with Sheer Force and Life Orb makes it the primary special wallbreaker on Poison-type teams, enabling it to threaten Steel, Water, Flying, and many other types with moves such as Thunderbolt, Fire Blast, Earth Power, and Ice Beam. Nidoking is also able to act as a Stealth Rock setter for the team, although it does require it to give up Thunderbolt, resulting in it getting walled by Mantine.
Gengar
Although it took a huge fall from what it was back in ORAS due to the loss of Levitate, Gengar still has a place on Poison teams as an offensive Ghost-type coupled with good Speed and Special Attack. Its Ghost typing allows it to excel in the Psychic matchup, as it's able to hit everything super effectively bar Meloetta and provide a Normal immunity for attacks such as Rapid Spin, Dragonite's Extreme Speed, and Diggersby's Quick Attack, which differentiates it from other offensive Poison-type Pokémon such as Nidoking and Nihilego; however, it is harder to fit compared to those Pokémon. It also has access to a decent range of coverage moves, namely Thunderbolt and Focus Blast, as well as the ability to use different items such as Choice Specs and Choice Scarf effectively.
Threats
Mega Diancie
Mega Diancie is able to pressure Poison-type teams using its coverage in Diamond Storm and Psychic. Psychic hits everything on Poison teams for super effective damage bar Alolan Muk, which Diamond Storm 2HKOes. Klefki's screens and Spikes support paired with Mega Diancie's Psychic + Diamond Storm coverage can be extremely obnoxious for Poison teams to beat, as Mega Venusaur fails to knock it out in one hit and cannot take two Psychics.
Mega Gallade
Using Close Combat and Zen Headbutt, Mega Gallade is able to hit everything on Poison-type teams with its Swords Dance-boosted STAB move combo. Although Crobat can check Mega Gallade, it cannot switch in on it, not to mention Psychic-type teams sometimes carry support in the form of Healing Wish to restore Mega Gallade to full health if it ever happens to get worn down. Mega Gallade, along with its team support, can be troublesome for Poison teams to deal with.
Kyurem-B
Kyurem-B threatens Poison teams because of its ability to use Earth Power, Ice Beam, and Fusion Bolt to break their defensive core as well as heal off damage using Roost. None of Poison's offensive Pokémon are able to switch into its Life Orb-boosted attacks.
Diggersby
Diggersby's strong STAB move combo in Return and Earthquake allows it to greatly damage Poison teams. Nothing can switch into Choice Band Diggersby for free on Poison, although it does have to face mind games with Toxapex and Crobat, especially if Toxapex is carrying Baneful Bunker. Swords Dance Diggersby is able to force Toxapex out via its strong Earthquake and can use Swords Dance in order to turn itself into a threatening wallbreaker and sweep the rest of the Poison team using its boosted attacks.
Mega Pinsir
Mega Pinsir is able to threaten Poison teams as a fierce wallbreaker that aims to rip through Poison's defensive core using Swords Dance-boosted Returns. Through Bug's Sticky Web support, Choice Scarf Nihilego can no longer hope to check Mega Pinsir by outspeeding it, and the Poison team therefore has to rely on Crobat to keep Mega Pinsir in check, which it cannot do effectively if chipped down beforehand.
Dragonite
Choice Band Dragonite is a devastating wallbreaker that is able to shred through Poison teams solely by using Outrage. Even physically bulky Pokémon such as Toxapex and Mega Venusaur simply get 2HKOed by it, and nothing else can take a hit otherwise. Poison teams have to get rid of its Multiscale and then use Ice Beam Nidoking and Hidden Power Ice Nihilego to even hope to check it.
Heatran
Heatran traps Toxapex, Alolan Muk, and Mega Venusaur with Magma Storm and breaks them all down with Earth Power and Taunt. Heatran's ability to trap and remove these three key defensive threats enables its teammates such as Mega Scizor, Jirachi, Mega Charizard X, and Blacephalon to do immense damage to the rest of the Poison team. None of Poison's offensive Pokémon are able to successfully switch into Magma Storm, as Gengar cannot take one, Nihilego gets trapped and knocked out by Earth Power, and Nidoking takes massive damage while being chipped down for later on in the game; however, Gengar and Nidoking are able to knock Heatran out with Focus Blast and Earth Power, respectively.
Good Matchups
Water
Water struggles to take on Poison due to the type's natural weakness to Mega Venusaur and susceptibility to being stalled out by it combined with Toxapex. Mega Venusaur is the main reason Water struggles to beat Poison, due to the fact that it can easily recover off most common coverage Water Pokémon have and slowly pick them off one by one with Giga Drain. Also, thanks to its ability to heal very reliably with Leech Seed and Synthesis, it becomes very annoying for Water teams very quickly. Water teams can't really break a core of Mega Venusaur + Toxapex very well. Strong wallbreakers that Poison has access to, such as Nidoking, can also prove to be troublesome for Water to deal with, as it can claim a KO practically each time it comes into a defensive wall like Toxapex thanks to its STAB Earth Power and coverage moves such as Thunderbolt. However, Poison teams do need to be careful of Dragon Dance Gyarados, as it can easily threaten Poison's defensive core due to a combination of Supersonic Skystrike and Earthquake and can break right past the offensive Pokémon.
Fairy
As many expect, due to Poison's natural type advantage against Fairy, it should do well in that matchup, and it does, particularly thanks to Toxic Spikes, which severely cripples all offensive Pokémon on Fairy teams and limits their time in the battlefield. On top of that, the defensive core of Mega Venusaur and Toxapex can easily tank most attacks Fairy teams throw at them. Mega Venusaur can take on Tapu Koko's and Tapu Bulu's Electric- and Grass-type attacks for Toxapex, while Toxapex has the ability to set Toxic Spikes and pressure Fairy teams by stalling out turns with Baneful Bunker, slowly chipping them down. Then, Poison's offensive Pokémon in Nidoking and Nihilego easily pressure Fairy teams, as their strong Poison STAB moves and great coverage make them hard to switch into, especially since Nidoking can beat Klefki thanks to Earth Power. However, Fairy teams can manage to beat Poison teams if they keep Toxic Spikes off the field and take advantage of some of their Pokémon's Psychic-type coverage moves, such as Tapu Bulu's Zen Headbutt and Mega Diancie's Psychic, allowing them to severely pressure Poison's defensive core.
Bad Matchups
Ground
Just as you might expect in Monotype, there are many unavoidable bad matchups thanks to the way the tier is set up. Poison versus Ground is a perfect example of just this, as Ground teams are easily able to muscle past Poison teams' defensive core with their strong STAB attacks. Since their usual checks to Ground STAB moves in Mega Venusaur and Crobat can be easily overpowered by a plethora of Pokémon on Ground teams such as Excadrill, Landorus, and Garchomp, Poison is left with few ways to defensively check Ground teams. It cannot do much better offensively, as Excadrill in sand absolutely devastates everything on Poison. This is thanks to Sand Rush and Swords Dance, which allow Excadrill to become a nearly uncheckable setup sweeper within the sand. While Mega Venusaur can be a nuisance to Ground-type Pokémon, it is easily worn down in the sand, as its recovery is severely nerfed while the sand is up, allowing it to be taken down much more easily. The best chance Poison has to neuter this offensive core that causes it so much trouble is hoping to take down Hippowdon, which is the team's sand setter and, by extension, what makes Excadrill a ferocious sweeper.
Dragon
While Dragon might not seem as obvious of a disadvantage for Poison as Ground, it is still no cakewalk. Thanks to Dragon teams generally carrying many powerful wallbreakers like Kyurem-B and Choice Band Dragonite, they can be hard for Poison teams to handle. Kyurem-B can easily take down Toxapex and Mega Venusaur with its BoltBeam coverage and can pick apart Alolan Muk with Earth Power. Dragonite can also always pick up at least one KO a game by coming in on a wall and simply clicking Outrage. Dragon's Stealth Rock user Garchomp also can pressure Poison teams with its ability to take on both of Poison's entry hazard setters and its Ground STAB moves, which are difficult for Poison teams to deal with. In return, Poison has to pressure Dragon teams with Toxic Spikes and find the perfect opportunity to bring in Nihilego and Nidoking to score a KO to possibly win the game.
Nihilego @ Choice Scarf
Ability: Beast Boost
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Power Gem
- Sludge Wave / Stealth Rock
- Hidden Power Ice
- Thunderbolt
Nidoking @ Life Orb
Ability: Sheer Force
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Stealth Rock / Thunderbolt
- Earth Power
- Ice Beam
- Fire Blast
Closing Words
Poison as a balanced type has shown a good amount of success in today's Monotype metagame both in casual and tournament play. Although it may revolve around the same few offensive and defensive Pokémon, it is a decent choice in Monotype nonetheless. If you ever feel like trying out different types in Monotype, be sure to give Poison a shot!