Marowak sets a good example by wearing a skull as a helmet, because it is recommending other Pokémon to do the same when he's around—his attacking power is right up there with giants like Slaking and Medicham. Sadly, a Pokémon with such great Attack must have drawbacks. Marowak is unable to utilize Leftovers, has very lackluster HP and Special Defense, and is not the quickest Pokemon out there. However, with paralysis, Trick Room, or Baton Pass support, Marowak can be a real wrecking ball.
With Thick Club doubling Marowak's Attack stat, the only thing stopping him from absolutely destroying the competition is his poor Speed and low defenses. In order to wreak havoc on the other team, Marowak needs some support from his teammates. The most effective form of support is paralysis. With a majority of the opposing team paralyzed, Marowak is free to come in on opponents who pose little threat to him, such as support Pokemon like Chansey or Registeel, set up a Substitute, and proceed to OHKO the opposition with the appropriate move. Earthquake is Marowak's strongest move when factoring in STAB, and is a force to be reckoned with. Double-Edge makes an appearance on this set thanks to its high Base Power and great coverage alongside Earthquake; as an added bonus, Marowak suffers no recoil from using it thanks to his Rock Head ability. The last slot is mostly filler. Fire Punch allows Marowak to hit Torterra and Tangrowth super effectively, which is very useful as defensive versions of both avoid a 2HKO from Double-Edge. ThunderPunch can also be useful as an opening move to scout for counters, and hits most Flying-types coming in to sponge an Earthquake for heavy damage.Team Options & Additional Comments >>>
In Trick Room, Marowak can invest more in Attack and HP, and also has room for another attacking move in place of Substitute; however, when Trick Room ends, Marowak is a sitting duck and can be easily OHKOed. He has access to a plethora of Fighting-type attacks, such as Focus Punch, Brick Break, and Low Kick, but they offer redundant coverage alongside Earthquake, and are rather inferior when compared to Double-Edge or Stone Edge. Bonemerang allows Marowak to break Substitutes, but most of the Pokemon who will be using Substitute against him aren't affected by Ground-type attacks. Marowak has access to Stealth Rock and Toxic, but he makes a much more effective attacker than a supporter.
Marowak also has access to Belly Drum if you're crazy enough to try it. With a Belly Drum boost alongside Thick Club and an Adamant nature, Marowak reaches an almost unimaginable Attack stat of 2,272; however, even with a Salac Berry boost, he will usually find himself outpaced and KOed by faster enemies before he can even land a hit. Marowak also has access to a plethora of special options such as Fire Blast and Ice Beam, but his Special Attack stat is low, and the aforementioned moves have little use outside of hitting Torterra and Tangrowth for more damage than his other moves—and only if he invests fully in Special Attack.
Checks and Counters
Marowak is rather defenseless if he isn't behind a Substitute, so Pokemon who can outpace and OHKO him make great checks. However, most Pokemon will be hard-pressed to switch into any of Marowak's attacks. Pokemon such as Venusaur, Sceptile, and Feraligatr all have no problem outrunning and OHKOing a Substitute-less Marowak. Tangrowth, Torterra, and Claydol can all avoid a 2HKO from any of Marowak's attacks (although Tangrowth and Torterra must be wary of Fire Punch) and can break his Substitutes and proceed to KO him.
If Marowak is in Trick Room, the best plan is to hit him with priority attacks. Azumarill can OHKO Marowak with Aqua Jet, while TechniTop can maim him with a combination of Fake Out and Mach Punch. Another strategy is to abuse Substitute and Protect as much as possible to burn Trick Room turns. Marowak also hates getting statused, especially burn, so Pokemon like Mismagius and Rotom can outrun Marowak and proceed to cripple him with Will-O-Wisp. However, neither can withstand getting hit by Fire Punch or Stone Edge, so this is a rather unreliable way of stopping Marowak, especially when both can easily 2HKO Marowak with Shadow Ball instead.