Lets give bobtheball4 a good amount of credit for his skeleton :p
Onix
[Overview]
<p>Despite often being overshadowed by Little Cup's other Rock- and Ground-types, Onix has created a niche for itself in that it is one of only two common leads in Little Cup that use Explosion. With Explosion and its above-average Speed, Onix is able to not only set up Stealth Rock, but also bring something down with it. Despite its usual reliability, it is still beaten by a number of common leads, most notably Snover, which easily OHKOes it. Nonetheless, you will find that Onix is a solid choice for most teams.</p>
Name: Lead
Move 1: Stealth Rock
Move 2: Earthquake
Move 3: Stone Edge
Move 4: Explosion / Taunt
Item: Focus Sash
Nature: Jolly
EVs: 76 HP / 236 Atk / 196 Spe
[Set Comments]
<p>Onix is able to do one thing extremely well: set up Stealth Rock. It is able to do this reliably by abusing two key attributes: its Defense and access to Explosion. With its sky-high Defense, Onix can laugh at the attacks Meowth and other Fake Out leads rely on to cause damage, while Onix sets up and starts firing off attacks. Onix can attack with either Earthquake or Stone Edge, as both receive the STAB boost and provide excellent coverage. In the final move slot, Explosion can get Onix a surprise kill once it has finished its job, while Taunt can stop every lead bar Diglett, Gligar, and Anorith from setting up entry hazards.</p>
[Additional Comments]
<p>While Onix is one of the more reliable leads in Little Cup, some common leads stop it cold. Snover deserves mention as it can OHKO Onix with Blizzard and negate Onix's Focus Sash due to hail damage. Munchlax is your best option against Snover, thanks to its Thick Fat ability and access to Fire Punch. Machop can use a combination of DynamicPunch and Bullet Punch to halt Onix in its tracks. Unfortunately, Machop is much harder to deal with due to the confusion that DynamicPunch brings, though Bronzor is a fairly safe bet with its STAB Psychic. Kabuto and Diglett are also problematic as they can set up and take Onix out with superior Speed or priority moves. Both will be left with 1 HP after Earthquake and the activation of Focus Sash, so any form of priority can deal with these two threats. Onix can use Protect over Explosion or Taunt in order to save itself against Aipom, but this allows Gligar to outclass Onix, as Onix's major advantage over Gligar is its access to Explosion.</p>
[Team Options]
<p>The main role that Onix serves is to set up Stealth Rock at the beginning of the battle. As such, teammates need to be able to deal with the threats that Onix can't and provide ample opportunity for it to switch in later in the game. Bronzor is a solid option to support lead Onix; it can check most of the leads that give Onix trouble, especially Snover and Diglett. Though usually a support Pokemon, Bronzor can abuse these opportunities to use Calm Mind, or just fire off attacks. Later in the game, Pokemon that commonly use Normal-type attacks, such as Taillow, provide easy opportunities for Onix to switch in.</p>
[Optional Changes]
<p>Unfortunately, Onix has a relatively shallow movepool, so any sets it does run are fairly limited in options; however, Onix is able to run a set designed for use in sandstorm. Thanks to its Rock-typing, Onix receives a substantial boost to its Special Defense in sandstorm, allowing it to successfully work in conjunction with Lileep. Onix is also capable of running a Rock Polish set, but it is outclassed in this regard by other Rock- and Ground-types, such as Rhyhorn and Geodude.</p>
[Counters]
<p>There are a variety of leads that give Onix trouble. Snover and Machop can both OHKO Onix with a STAB attack combined with a priority attack. Aipom can take Onix out with Fake Out and Seed Bomb before it can hit back. Not only can Diglett set up on Onix, but it also outspeeds it and can fire off a faster Earthquake. With a combination of Waterfall and Aqua Jet, Kabuto can render Onix useless.</p>
<p>Gligar is bulky enough to absorb a Stone Edge and fire off its own Earthquake. Bronzor, though afraid of Taunt, laughs off any attack Onix throws at it and sets up whatever it needs to. Onix is prone to priority, taking super effective damage from Ice Shard, Mach Punch, Vacuum Wave, and Aqua Jet; as such, any moderately powerful priority user will make short work of Onix.</p>

Onix
[Overview]
<p>Despite often being overshadowed by Little Cup's other Rock- and Ground-types, Onix has created a niche for itself in that it is one of only two common leads in Little Cup that use Explosion. With Explosion and its above-average Speed, Onix is able to not only set up Stealth Rock, but also bring something down with it. Despite its usual reliability, it is still beaten by a number of common leads, most notably Snover, which easily OHKOes it. Nonetheless, you will find that Onix is a solid choice for most teams.</p>
Name: Lead
Move 1: Stealth Rock
Move 2: Earthquake
Move 3: Stone Edge
Move 4: Explosion / Taunt
Item: Focus Sash
Nature: Jolly
EVs: 76 HP / 236 Atk / 196 Spe
[Set Comments]
<p>Onix is able to do one thing extremely well: set up Stealth Rock. It is able to do this reliably by abusing two key attributes: its Defense and access to Explosion. With its sky-high Defense, Onix can laugh at the attacks Meowth and other Fake Out leads rely on to cause damage, while Onix sets up and starts firing off attacks. Onix can attack with either Earthquake or Stone Edge, as both receive the STAB boost and provide excellent coverage. In the final move slot, Explosion can get Onix a surprise kill once it has finished its job, while Taunt can stop every lead bar Diglett, Gligar, and Anorith from setting up entry hazards.</p>
[Additional Comments]
<p>While Onix is one of the more reliable leads in Little Cup, some common leads stop it cold. Snover deserves mention as it can OHKO Onix with Blizzard and negate Onix's Focus Sash due to hail damage. Munchlax is your best option against Snover, thanks to its Thick Fat ability and access to Fire Punch. Machop can use a combination of DynamicPunch and Bullet Punch to halt Onix in its tracks. Unfortunately, Machop is much harder to deal with due to the confusion that DynamicPunch brings, though Bronzor is a fairly safe bet with its STAB Psychic. Kabuto and Diglett are also problematic as they can set up and take Onix out with superior Speed or priority moves. Both will be left with 1 HP after Earthquake and the activation of Focus Sash, so any form of priority can deal with these two threats. Onix can use Protect over Explosion or Taunt in order to save itself against Aipom, but this allows Gligar to outclass Onix, as Onix's major advantage over Gligar is its access to Explosion.</p>
[Team Options]
<p>The main role that Onix serves is to set up Stealth Rock at the beginning of the battle. As such, teammates need to be able to deal with the threats that Onix can't and provide ample opportunity for it to switch in later in the game. Bronzor is a solid option to support lead Onix; it can check most of the leads that give Onix trouble, especially Snover and Diglett. Though usually a support Pokemon, Bronzor can abuse these opportunities to use Calm Mind, or just fire off attacks. Later in the game, Pokemon that commonly use Normal-type attacks, such as Taillow, provide easy opportunities for Onix to switch in.</p>
[Optional Changes]
<p>Unfortunately, Onix has a relatively shallow movepool, so any sets it does run are fairly limited in options; however, Onix is able to run a set designed for use in sandstorm. Thanks to its Rock-typing, Onix receives a substantial boost to its Special Defense in sandstorm, allowing it to successfully work in conjunction with Lileep. Onix is also capable of running a Rock Polish set, but it is outclassed in this regard by other Rock- and Ground-types, such as Rhyhorn and Geodude.</p>
[Counters]
<p>There are a variety of leads that give Onix trouble. Snover and Machop can both OHKO Onix with a STAB attack combined with a priority attack. Aipom can take Onix out with Fake Out and Seed Bomb before it can hit back. Not only can Diglett set up on Onix, but it also outspeeds it and can fire off a faster Earthquake. With a combination of Waterfall and Aqua Jet, Kabuto can render Onix useless.</p>
<p>Gligar is bulky enough to absorb a Stone Edge and fire off its own Earthquake. Bronzor, though afraid of Taunt, laughs off any attack Onix throws at it and sets up whatever it needs to. Onix is prone to priority, taking super effective damage from Ice Shard, Mach Punch, Vacuum Wave, and Aqua Jet; as such, any moderately powerful priority user will make short work of Onix.</p>