Arena Trap - Lead spot: 100% higher chance of encountering wild pokemon.
Compoundeyes - Lead spot: Chance of encountering a wild Pokemon holding an item increases.
Cute Charm - Lead spot: 66.6% chance of encountering a wild Pokemon of the opposite gender. No effect on swarming Pokemon.
Flame Body - Eggs hatch in half as many steps with Pokemon in party. (Cannot stack multiple of this ability or Magma Armor.)
Hustle - Lead spot: 50% higher chance of encountering a high level wild Pokemon.
Illuminate - Lead spot: 100% higher chance of encountering wild Pokemon.
Intimidate - Lead spot: 50% lower chance of encountering a low level wild Pokemon.
Keen Eye - Lead spot: 50% lower chance of encountering a low level wild Pokemon.
Magma Armor - Eggs hatch in half as many steps with Pokemon in party. (Cannot stack multiple of this ability or Flame Body.)
Magnet Pull - Lead spot: 50% higher chance of encountering a Steel-type wild Pokemon.
No Guard - Lead spot: 50% higher chance of encountering a wild Pokemon.
Pressure - Lead spot: 50% higher chance of encountering a high level wild Pokemon.
Quick Feet - Lead spot: 50% lower chance of encountering a wild Pokemon.
Sand Veil - Lead spot: 50% lower chance of encountering a wild Pokemon while in a sandstorm.
Snow Cloak - Lead spot: 50% lower chance of encountering a wild Pokemon while in a hailstorm.
Static - Lead spot: 50% higher chance of encountering an Electric-type wild Pokemon.
Stench - Lead spot: 50% lower chance of encountering a wild Pokemon. (25% lower in Battle Pyramid.)
Sticky Hold - Lead spot: Easier to catch Pokemon when fishing.
Suction Cups - Lead spot: Easier to catch Pokemon when fishing.
Swarm - Lead spot: 50% higher chance of encountering a wild Pokemon. Emerald-exclusive: Can more often hear the roars of common wild Pokemon.
Synchronize - Lead spot: 50% chance of encountering a wild Pokemon with the same nature.
Vital Spirit - Lead spot: 50% chance of encountering a high level wild Pokemon.
White Smoke - Lead spot: 50% lower chance of encountering a wild Pokemon.
Source:
https://www.reddit.com/r/pokemon/comment...t_find_so/