Smeargle @ Focus Sash
Trait: Own Tempo
EVs: 252 Spd / 4 HP / 252 Atk
Jolly Nature
- Spore
- Stealth Rock
- Spikes
- Explosion
I <3 Smeargle. It is just so good at getting up spikes and sr early game, and that damage is really important for many, many 1 and 2HKO's, and the extra residual damage from spikes allows you to wear down esca, druddigon, steelix, qwilfish, entei etc. much quicker than with just sr. Smeargle also allows you to get momentum early game, and helps stop sr going up early game from rhydon, steelix and piloswine among others. Spore is an incredibly useful weapon, as the sleep mechanics basically mean you can never wake up if the opponent is good, since if they switch in an asleep poke, you can just go straight to another poke and force them out, wracking up hazard damage in the process. I prefer Explosion on smeargle more than whirlwind, as although it leaves you completely stuck against sub rotom and some other sub users, boom leaves a mark on a number of frail attackers hoping to set-up and still breaks the substitutes of most pokemon in the tier due to the STAB on explosion. It also helps a ton against kabutops and cryogonal. Cryo is outright 1HKO'd, and since most only aim to outspeed modest queen, smeargle usually gets the jump on them, while kabutops, if adamant, can't spin away hazards since smeargle will be dead so your hazards stay up. With whirlwind, kabutops / cryo can come in for free after a spore and unless you have a spinblocker, you're hazards will be eliminated straight away.
Basically any offensive poke will benefit from spikes, but some much more so than others. Moltres really likes spikes, allowing it to wear down rhydon, regirock and lanturn much more quickly than with just sr. Rotom-C and sceptile also appreciate from spikes, as two of their best counters, druddigon and escavalier, are grounded and much easier to wear down with spikes and sr. Rotom-C can also use volt switch to wrack up hazard damage. Having a spin-blocker, such as rotom or spiritomb, is also useful as rotom can stop sandslash from spinning, and tomb can stop cryogonal from spinning freely. Kabutops smashes straight through both of them though, and every other spinblocker for that matter.
There are lots of ways to stop smeargle setting up sr+spikes+spore, and speed ghilliesniper provided a good list above. You can also use fast taunters such as qwilfish and aerodactyl, although magic coat smeargle beats these leads. Kangaskhan and Cincinno are probably the best ways to deal with it, as they stop smeargle doing anything at all unless it is mighty scarf smeargle.
tl;dr: Smeargle is the best offensive spiker in the tier, and is excellent at doing its job and should be used much more than it is.