With a fantastic ability in Guts and two good boosting moves in Rock Polish and Dragon Dance, Larvitar makes a great set-up sweeper. Not only that, but Larvitar also hits just enough Speed to outspeed all unboosted Pokemon after a Dragon Dance. It also gets near-perfect coverage with its dual STAB attacks. Unfortunately, Larvitar has weaknesses to common priority attacks such as Aqua Jet, Mach Punch, Vacuum Wave, and Bullet Punch, which really limits its effectiveness.
As a set-up sweeper, Larvitar can run a threatening boosting set with either Dragon Dance or Rock Polish as its boosting move. Dragon Dance is the preferred option, as it allows Larvitar to muscle through Pokemon holding an Eviolite. However, you can also use Rock Polish to outspeed all Choice Scarf users that have 17 Speed or less.
When using Dragon Dance, a Jolly nature is recommended as Larvitar will hit 21 Speed after a Dragon Dance, which is enough to outspeed every unboosted Pokemon, while still reaching a huge 36 Attack stat. However, when using Rock Polish, an Adamant nature is recommended, as Larvitar needs all the power it can get. A Jolly nature is still an option, though, to at least tie with all Choice Scarf users with 19 Speed or less, such as Staryu and Taillow. Earthquake is Larvitar's most reliable STAB move and a staple on any set. Stone Edge is the main option in the third moveslot because of its high Base Power which is further boosted by STAB. Rock Slide can also be used instead of Stone Edge for the higher accuracy it provides, but it loses out on a lot of power. Crunch is a more reliable move for hitting Gastly, but Facade is also a great option in the last slot, as its Base Power is doubled to a huge 140 when Larvitar is afflicted with a status condition.Team Options & Additional Comments >>>
Substitute can help Larvitar take priority attacks and eases prediction, but comes at the cost of a moveslot. Larvitar is also immune to status anyway, courtesy of Flame Orb and Guts. Outrage provides good neutral coverage, but its secondary effect makes it a bad option. Superpower hits Bronzor the hardest out of all of Larvitar's moves, but the Attack drop is undesirable. Curse can be used along with Sandstorm support and an Eviolite, but Larvitar's common 4x weaknesses make it a bad choice.
Larvitar can also run a Choice Scarf set, as it then outspeeds all unboosted Pokemon, hitting 21 Speed. It also has Guts and a Thunder Wave immunity to set it apart from other Choice Scarf users, but its lack of power lets it down. Larvitar can also run a Choice Band set as it makes a good status absorber with Guts, but it is outclassed by Rhyhorn and Geodude.
Checks and Counters
Pokemon with powerful priority attacks are Larvitar's best checks. Aqua Jet users such as Totodile and Kabuto, as well as Mach Punch users such as Timburr, are good examples.
Choice Scarf users with super effective attacks, such as Chinchou, can revenge kill Dragon Dance Larvitar easily. The Rock Polish set is much harder to revenge kill, as only Choice Scarf users with 20 Speed or higher, such as Diglett and Elekid, can revenge kill it. Fortunately, it is much easier to wall Rock Polish Larvitar, so using a bulky Pokemon such as Bronzor, Frillish, or Ferroseed should suffice.
Bronzor is probably the best counter to Larvitar, as it resists both of Larvitar's STAB attacks and can OHKO it with STAB Gyro Ball.