What it does
Infestation hits for damage and applies a trapping effect: the target can't switch out or flee for 2-5 turns, and takes 1/16 of its max HP at the end of each of those turns. The user can keep acting normally during this window. If the user switches out, the trap ends immediately.
In doubles, the trapped Pokémon can still attack normally — it just can't switch. That's a real restriction in a format where pivoting is often the difference between a good and bad turn. Rapid Spin removes the trapping effect, which is the most common out opponents reach for.
Who runs it
Toxapex at 53%. It runs Infestation alongside Baneful Bunker: trap a target with Infestation, then alternate protection moves while the 1/16 chip and other damage stack up. The target can't escape and slowly bleeds out. Toxapex's raw bulk is what makes this loop viable — it has to survive long enough for the per-turn damage to add up.
How to use it
Target something you want pinned — the opponent's win condition, their weather setter, their Trick Room user. Trapping something irrelevant wastes the move. Once the target is locked, rotate protection moves. The trapped Pokémon bleeds 1/16 per turn; add poison or other chip and a full-health Pokémon can reach the danger zone in just a few turns.
Don't switch Toxapex out after landing Infestation — the trap ends the moment the user leaves the field. Stay in and keep the loop going.
Tips & strategy
Infestation is somewhat weaker in doubles than singles because the opponent still has a free Pokémon acting every turn. Trapping one doesn't stop the other from putting pressure on your side. The move works best when your partner is already controlling the other Pokémon — Toxapex traps the primary threat while your partner deals with the second. That coordination is what makes the lock matter.
Rapid Spin is the clean answer: it removes trapping effects, giving the pinned Pokémon its switch back. If your opponent has a Rapid Spin user, factor that into whether Infestation is worth running at all in a given matchup.