Leech Seed plants a seed on the target that activates at the end of every turn: the target loses 1/8 of its max HP, and that HP is transferred as healing to the Pokémon that planted the seed (even if that Pokémon has switched out — the healing still goes to whichever Pokémon is currently on the field in that spot).
Grass-type Pokémon are completely immune to Leech Seed.
Why Whimsicott stars it
WhimsicottWhimsicottpokemonPrankster utility lead. Priority Tailwind, Encore, and Sunny Day let it dictate tempo against teams that thought they had it.Click to read more → is the canonical Leech Seed user in Reg M-A. PranksterPranksterabilityAn ability that gives all Status moves +1 priority — they go before almost everything, even if the Pokémon is slow.Click to read more → gives Leech Seed +1 priority, which means the seed always lands before the opposing turn 1 attacker can move:
- Prankster raises Leech Seed to +1 priority
- The seed plants before the opponent can switch, attack, or set up
- Whimsicott pivots out next turn — EncoreEncoremoveForces the target to repeat their last move for 3 turns — devastating in doubles when it traps a Protect or harmless status move.Click to read more →, U-turn, or another support move — while the seed keeps draining
Over a 4–6 turn game, this chip silently moves an opposing Pokémon from full HP to critical without Whimsicott ever using a damaging move slot. The opponent is forced to spend switch turns clearing the seed or eat the chip every end-of-turn.
Doubles dynamics
Leech Seed is a single-target move — it can only be planted on one of the two opposing Pokémon per turn. In doubles, the opponent can switch out the seeded Pokémon to remove the effect, leaving Whimsicott to re-seed if it can. This creates a tempo game around whether the opponent wants to spend switch turns removing seeds.
Whimsicott Leech Seed pairs with bulky partners — IncineroarIncineroarpokemonThe most-used Pokémon in Reg M-A. Defines doubles tempo with Fake Out, Intimidate on every switch, and Parting Shot pivots.Click to read more →’s IntimidateIntimidateabilityWhen this Pokémon enters the battlefield, the opposing Pokémon's Attack stat drops by one stage.Click to read more → cycle and Sinistcha’s HospitalityHospitalityabilityRestores 25% of the partner's max HP when this Pokémon enters the field.Click to read more → heals both buy turns for the seed to work. Trevenant (Harvest + Sitrus Berry) is the secondary in-roster Leech Seed user: slower than Whimsicott but recycles its berry for sustained drain.
Fails against Grass types
Since Grass types are immune, Whimsicott can’t Leech Seed opposing Pokémon like Venusaur, Meowscarada, Sinistcha, or Tsareena. Against Grass-heavy teams, Leech Seed’s value drops to zero.