What it does
Grass Knot is a Grass-type special contact move. Power depends on the target's weight in six tiers: 20 for under 10 kg, 40 for under 25 kg, 60 for under 50 kg, 80 for under 100 kg, 100 for under 200 kg, and 120 for 200 kg and above. Most of the heavy Water, Rock, and Ground-type threats you'll face fall into the 100–120 range, which is where the move's competitive value lives.
Who runs it
Pikachu runs Grass Knot in about 12% of teams. Its Special Attack is modest, but Grass hits Water, Rock, and Ground super effectively — exactly the types that absorb Electric moves and do nothing in return. This isn't a high-damage tech; it's a coverage slot that makes those matchups not auto-lose.
How to use it
Get into the habit of knowing your opponent's weight before you click it. Gyarados weighs 235 kg — that's 120 BP before the super effective multiplier. Snorlax at 460 kg, Steelix at 400 kg — same ceiling. But Vaporeon is only 29 kg, which means 40 BP out of a move you expected to threaten. The inconsistency is the move's biggest weakness.
Grass Knot hits one target in doubles, so there's no spread penalty. When you're facing a known-heavy target, click it — no hesitation.
Tips & strategy
Do a quick weight check on the main threats in your opponent's team before the match. For standard big targets like Gyarados or Snorlax, you already know. Where it gets tricky is off-meta picks where you don't know the weight off the top of your head. If you're uncertain, use another move first and save Grass Knot for confirmed heavy targets. The last thing you want is to click it expecting 120 BP and get 40.