Nihilego is the current most used Hazard setter from Sun/Moon, with great speed, and access to Toxic Spikes and Stealth Rock.
Other popular Pokemon include
- Deoxys Defense (Stealth Rock / Taunt / Spikes / Recover / Seismic Toss)
- Ferrothorn (Stealth Rock / Thunder Wave / Leech Seed / Spikes)
- Forretress (Stealth Rock / Rapid Spin / Thunder Wave / Volt-Switch / Spikes / Explosion)
- Skarmory (Stealth Rock / Spikes / Whirlwind / Brave Bird)
- Tentacruel (Toxic Spikes / Scald / Rapid Spin)
- Hippowdown/Tyranitar (Stealth Rock)
Some Pokemon work great on paper but are not used much, like Ariados, with access to Sticky Web and Toxic Spikes. Unfortunately, poor speed and awkward typing mean it's nowhere as popular as other choices.
Thus, some common trends apart from learning hazard moves that make Hazard Setters popular are
- Great speed (or) Great Defenses
- Ability to Taunt other Leads
- Access to phasing moves (Roar/Whirlwind)
- Access to crippling moves
- Ability to retaliate strongly despite Taunt
As for me, my favourite is a slightly uncommon (the Pokemon, not the set) one I use:
Azelf @ Focus Sash
252 Speed / Rest in HP and Attack
Jolly (+Speed, - Special Attack)
- Taunt
- Knock Off
- Stealth Rock
- Explosion
