Moves
With Pursuit, Alolan Grimer can trap threats such as Abra and Gastly while also trapping weakened foes such as Pumpkaboo-XL and Slowpoke. Knock Off is a powerful Dark-type STAB move with the bonus effect of removing items. Both of these moves also come with a 30% chance of poisoning foes thanks to Poison Touch. Poison Jab is the preferred move in the third moveslot because it has perfect accuracy, hits decently hard, and boasts an increased 51% chance of poisoning. On the other hand, Gunk Shot trades these for more power, notably OHKOing Spritzee after Stealth Rock damage most of the time. For the last moveslot, Shadow Sneak can be used to pick off weakened targets and to bypass Alolan Grimer's terrible Speed. Alternatively, Fire Punch hits the Steel-types that check Alolan Grimer, with a good chance to OHKO Ferroseed after one layer of Spikes and a guaranteed 2HKO on non-Eviolite Magnemite and Pawniard.
Set Details
Maximum Attack investment is required to make Alolan Grimer hit as hard as possible. The leftover EVs are dumped into its defensive stats because it doesn't need Speed at all; they guarantee that Alolan Grimer is never 2HKOed by Life Orb Abra's Dazzling Gleam and, for Eviolite variants, never OHKOed by Jolly Focus Sash Diglett's Earthquake. Eviolite is the prime item of choice because it boosts Alolan Grimer's defenses to let it take hits better. Berry Juice, on the other hand, lengthens its lifespan, since it lacks any form of recovery. An alternative EV spread of 36 HP / 196 Atk / 36 Def / 196 SpD lets Alolan Grimer check Abra and Gastly more reliably but sacrifices some needed physical bulk, while a spread of 36 HP / 36 Atk / 196 Def / 196 SpD grants better mixed bulk to avoid most OHKOs but at the cost of significant offensive presence.
Usage Tips
Alolan Grimer should spam Knock Off most of the time because it is a powerful STAB move with great utility and a good chance of poisoning; it should use Knock Off even if a Fairy-type such as Snubbull is switching in because removing its item helps with punishing it with Poison Jab or Gunk Shot later. Knock Off is also a good source of chip damage, increasing the chances to OHKO foes with Poison Jab. Pursuit severely dents fleeing foes, and the added bonus of possibly poisoning them is very useful because it deals some chip damage. Alolan Grimer should be sent in on Pokemon it can Pursuit trap, such as Abra and Gastly, because it can survive most hits and KO them back. Alolan Grimer is able to survive most powerful hits thanks to its typing and its bulk; however, keep in mind that it lacks a solid form of recovery besides Berry Juice. Finally, be wary of Volt Switch or U-turn users that can bring Diglett in, as Alolan Grimer is very vulnerable to it.
Team Options
Alolan Grimer can pair well with the majority of setup sweepers of the tier: Nasty Plot Vullaby is an exceptional partner and forms a Dark-type core with Alolan Grimer. Vullaby appreciates Alolan Grimer's Knock Off and ability to remove Fairy-types thanks to its Poison typing; on the other hand, Alolan Grimer loves Vullaby's ability to switch into Ground-type moves. Shell Smash Tirtouga pairs well with Alolan Grimer because it can remove opposing Eviolites and check Grass-types; in exchange, Tirtouga checks some Ground-types and picks off Diglett when its Focus Sash has been broken. Alolan Grimer struggles a lot against Ground-types such as Diglett, Mudbray, and Hippopotas because they can KO it; powerful attackers with access to priority moves, such as Dragon Dance Corphish and Carvanha, make for great partners, picking off Diglett and severely denting Mudbray and Hippopotas. Cleric support is deeply appreciated because Alolan Grimer doesn't have a solid form of recovery besides Berry Juice and suffers from burns: Spritzee can be a good partner, providing both Wish and Aromatherapy support to heal Alolan Grimer; Snubbull can weaken physical attacks that target Alolan Grimer thanks to Intimidate and provide Heal Bell support to remove burns; Z-Memento Cottonee can restore Alolan Grimer's health when it is low, soften an opposing sweeper, and also take on the Ground-types that Alolan Grimer hates. Fighting-types appreciate Alolan Grimer as a Psychic-, Ghost-, and Fairy-type check; Timburr, Mienfoo, and Pancham pair well with it, removing the Steel-types that check it. Finally, Grass-types such as Foongus and Pumpkaboo-XL can check the Ground-types that threaten Alolan Grimer.