Moves
Earthquake is an extremely powerful STAB attack coming off the given Attack investment and Life Orb, allowing Drilbur to put a dent in anything that doesn't resist the move. Rock Slide is great coverage alongside Earthquake, hitting Flying-types such as Rufflet and Vullaby as well as the likes of Larvesta and Dwebble for super effective damage. Shadow Claw allows Drilbur to hit Pumpkaboo-XL, a traditional Ground-type check, for a 2HKO on the switch while also 2HKOing Slowpoke after Stealth Rock. Rapid Spin can be used to trade coverage for quick entry hazard removal, though it is worth noting that Drilbur's frailty requires the move to be used sparingly. Poison Jab, however, is also an option that rounds off Drilbur's coverage, allowing it to OHKO Grass-types that otherwise wall it, such as Snivy and Cottonee.
Set Details
Maximum investment in Attack puts as much power behind Drilbur's attacks as possible, while a Life Orb allows Drilbur to secure the 2HKO on Pumpkaboo-XL with Shadow Claw as well as the 2HKO on Foongus and the OHKO on Sturdy Onix with Earthquake thanks to Mold Breaker. Groundium Z is an option over Life Orb, as it can aid Drilbur in breaking past especially bulky foes, such as Spritzee and Ferroseed. Maximum investment in Speed with a Jolly nature allows Drilbur to hit 17 Speed and thus outpace a large portion of the metagame. The remaining EVs are invested in HP to minimize Life Orb recoil. Mold Breaker is the ability of choice, as it allows Drilbur to bypass abilities like Levitate and Sturdy to OHKO Pokemon like Gastly, Onix, and Dwebble.
Usage Tips
This set takes a more offensive approach, but it can still function as a decent anti-lead due to its ability to defeat common leads in Sturdy Onix and Omanyte. Drilbur should be especially wary of switching into attacks when holding a Life Orb, as with this set it has even worse bulk. Thus, slow pivot support or the loss of a teammate is mandatory for safely bringing Drilbur into play. This set is rather reliant on careful prediction for its success, as Drilbur will only be able to 2HKO Pokemon like Vullaby, Slowpoke, and Pumpkaboo-XL if it hits them with a super effective coverage move on the switch. If Drilbur is running Rapid Spin over Poison Jab, it should use the move when predicting the switch to a Pokemon that it can't hit for notable damage, such as Cottonee or Snivy. Drilbur's Speed, while good, still leaves it outpaced by a few common Pokemon, such as Abra, Staryu, and Gastly, which means that these threats should be switched out of earlier in the game in order to preserve Drilbur and removed for late-game if Drilbur wishes to clean up.
Team Options
Stealth Rock support is extremely useful, as it allows Drilbur to secure KOs on Pokemon it would otherwise struggle to break in Slowpoke and Vullaby. Onix, Dwebble, and Pawniard are all capable of supporting Drilbur with Stealth Rock, while the latter two can also provide support in the form of Knock Off. Other users of Knock Off, such as Alolan Grimer, Vullaby, and Cottonee, can also be used to remove Eviolites and help Drilbur break past bulkier threats, as well as to remove Choice Scarfs to help prevent Drilbur from being revenge killed. Checks to bulky Water-types, which can be quite the nuisance to Drilbur, are quite helpful as teammates. Examples include Snivy, Elekid, Magnemite, and Chinchou. If Drilbur isn't running Poison Jab, Grass-type checks are also quite helpful. Rufflet, Doduo, and Ponyta can all function as reliable answers to the Grass-types that otherwise trouble Drilbur. Ponyta, Houndour, and Vullaby all appreciate Drilbur's Rapid Spin support if it's running the move and can also aid it in removing the Grass-type Pokemon it hates dealing with. Setup sweepers like Corphish, Vullaby, and Pawniard are also appreciative of Drilbur, as it can break past the defensive Pokemon that they tend to struggle with. Lastly, while not mandatory, Sticky Web support from the likes of Surskit and Spinarak is useful for allowing Drilbur to outpace and KO Pokemon that would otherwise tie or outspeed it, such as Abra, Cottonee, Gastly, and Mienfoo.