Meganium

Base stats, and where each one ranks among the 234 Pokémon legal in Regulation M-B.
Stat	Base	Rank
HP	80	110th
Attack	82	142nd
Defense	100	59th
Sp. Atk	83	120th
Sp. Def	100	52nd
Speed	80	113th
Total	525	70th

Legal, but nobody plays it

Meganium is legal in Regulation M-B and did not appear often enough on the ladder to produce usage statistics. It is legal and simply out of favour, which makes it unmeasured rather than unusable.

The Pokémon itself

Meganium is number 154 in the National Dex, a Johto Pokémon, Grass with a base stat total of 525 — 70th of the 234 Pokémon legal in this regulation. Its best stat is Defense at 100, 59th in the format; its weakest is Speed at 80, 113th. It can have Overgrow and Leaf Guard. The Champions module tiers it UU.

It sits in a 3-stage line: Chikorita → Bayleef → Meganium. Not all of that line is legal in this regulation — Chikorita and Bayleef are not.

What gets through

As Grass, 5 of the eighteen attacking types do extra damage to it. It resists 4. The board above has all of it. 5 other legal Pokémon share the same typing and the same board: Tsareena, Serperior, Sceptile, Leafeon, Simisage.

What threatens it

Smogon publishes no head-to-head checks-and-counters data for doubles formats, so this list is computed, not measured: the most-played Regulation M-B Pokémon carrying a damaging move of a type Meganium takes extra damage from.

Incineroar — Flare Blitz (Fire, ×2), on 91.2% of its sets
Charizard-Mega-Y — Heat Wave (Fire, ×2), on 99.2% of its sets
Sneasler — Dire Claw (Poison, ×2), on 63% of its sets
Pelipper — Hurricane (Flying, ×2), on 98.1% of its sets
Staraptor-Mega — Brave Bird (Flying, ×2), on 83.4% of its sets
Aerodactyl-Mega — Dual Wingbeat (Flying, ×2), on 91.2% of its sets

Speed and weight

At level 50 with a boosting nature and full investment, Meganium reaches 145 Speed; left uninvested with a neutral nature it sits at 100. Invested, it outruns 10 of the 20 most-used Pokémon in the regulation when they are invested too — which is the comparison that decides who moves first.

It weighs 100.5 kg, so Grass Knot and Low Kick hit it for 100 base power. That is a real consideration in a format where both are common.

Its move pool

Meganium learns 95 moves in the Champions data. 50 of them do damage, across 11 of the eighteen types, and 16 share a type with it and so get the same-type bonus. Its hardest-hitting same-type move is Frenzy Plant at 150 base power. It has no priority move, so it moves in Speed order every turn.

That pool is what the team builder reads from when you seat it, and the damage calculator will take it as the attacker with the form already chosen.

Taking damage