Moves
Stealth Rock can severely weaken the opponent's team over time, and Gible's high offensive presence allows it to set up the entry hazard on switches it forces while continuing to threaten its foe afterwards. Draco Meteor is a very powerful STAB move that hits most of the metagame hard. However, since it lowers Gible's Special Attack, it will usually force Gible to switch out. Earth Power is a secondary STAB move that has great neutral coverage with Draco Meteor, notably hitting Steel-types such as Pawniard and Magnemite, which resist Draco Meteor, super effectively, OHKOing non-Eviolite variants of the former and all variants of the latter, as well as hitting Fairy-types like Snubbull neutrally, nearly always 2HKOing it after Stealth Rock if its item has been removed or consumed. Fire Blast is a great coverage move, hitting all three Pokemon that resist both of Gible's STAB moves super effectively, 2HKOing Bronzor and Cottonee while usually 2HKOing Morelull after Stealth Rock. In addition, it 2HKOes Ferroseed, which can take any of Gible's other moves with ease.
Set Details
Berry Juice is used in order to make up for Gible's lack of recovery and greatly increase its longevity. Eviolite is an option over Berry Juice to allow Gible to tank hits a bit better, but it usually prefers the Berry Juice's recovery. The defensive investment and a Bold nature increase Gible's bulk by a good amount, notably allowing it to nearly always take two Drain Punches from Croagunk, one Shadow Ball from Life Orb Gastly, one Analytic-boosted Flash Cannon from Choice Scarf Magnemite, and one Hydro Pump from Life Orb Staryu. The remaining EVs are put into Speed and Special Attack to increase Gible's offensive presence. An alternative EV spread of 52 HP / 156 Def / 196 SpA / 76 SpD / 20 Spe can be used in order to hit harder, as this notably lets Gible OHKO Ferroseed and gives it a chance to OHKO Cottonee without an Eviolite with Fire Blast after Stealth Rock. However, this will make Gible struggle to take the special hits mentioned above, and since Gible outspeeds Ferroseed, it will be forced to take two Fire Blasts before going for a move itself if it switches in on Gible anyway, meaning that this spread is generally not worth it. Rough Skin is used to punish physical attackers, though the damage is fairly insignificant. A specially attacking set is used despite Gible's higher Attack because these moves have very good coverage together and this set can utilize them without sacrificing Gible's bulk, whereas a mixed set would be forced to move some defensive EVs to offensive stats to achieve certain OHKOs and 2HKOs. In addition, it allows Gible to more easily check Fire-types like Ponyta and Larvesta, which often carry Will-O-Wisp and could thus cripple a physical or mixed set.
Usage Tips
Gible should focus on using its offensive presence to force a switch and set up Stealth Rock. If Gible is still holding its Berry Juice, it can be used to take a hit from strong attackers like Timburr and fire off a powerful Draco Meteor. Gible can also be used as a suicide lead if your team really needs it to set Stealth Rock up, as its decent bulk allows it to usually do so after taking a hit. Since Gible's bulk is only decent and it lacks recovery outside of Berry Juice, it should usually only switch in on Pokemon it is able to check easily like Ponyta and Elekid—otherwise, it can easily be worn down. If Gible is used to check Chinchou, it should be scouted to make sure it doesn't carry Ice Beam, as that can easily OHKO Gible. Gible can come in on Pokemon that are reliant on recoil moves, such as Doduo and Darumaka, in order to wear them down even faster thanks to Rough Skin. It does need to be careful, however, as it can be significantly crippled if it switches in on Doduo's Knock Off, and very powerful moves like Rufflet's Brave Bird will OHKO it.
Team Options
Fairy-types like Spritzee and Snubbull appreciate Gible threatening Poison-, Steel-, and Fire-types. Steel-types like Pawniard and Ferroseed check Ice-, Dragon-, and Fairy-types for Gible, while Gible threatens Fire-types in return. Ferroseed can also set up Spikes, which synergizes nicely with Gible's Stealth Rock, while Pawniard deters Defog, which allows Gible's Stealth Rock to stay up longer. Other Spikes setters such as Dwebble and Trubbish can also stack entry hazards with Gible and capitalize on the switches it forces. Dwebble also appreciates Gible threatening Rock-types. Powerful wallbreakers like Mienfoo and Pawniard can force a lot of switches, thus capitalizing on Gible's Stealth Rock. Setup sweepers like Shell Smash Shellder and Nasty Plot Vullaby appreciate Gible's Stealth Rock, as it allows them to break through their checks more easily. Since Gible can check Pokemon like Elekid and Magnemite quite well, Pokemon that appreciate that, such as Doduo and Vullaby, are good partners.