Ekans

It starts a two-stage evolutionary line and wraps it up quickly: at level 22, its body broadens, the hood with the painted face appears, and it becomes Arbok. Before that, it is a two-metre snake weighing 6.9 kilograms. The proportions are the first thing that stand out — two metres long but under seven kilograms — and explain why it looks like a rope with eyes in the games.

The Pokédex entries keep coming back to the same points. It grows with age, with no requirement beyond the passage of time, and spends its nights coiled around tree branches. It eats the eggs of bird Pokémon, and the entries name names: Pidgey and Spearow. It swallows them whole, and one of them adds that it sometimes chokes and loses consciousness.

Like real snakes, it can dislocate its jaw to swallow prey larger than itself, then coils up to digest it. That posture is more than just resting. Coiled up with its head raised, it can respond to a threat from any direction, which is where the entries insist on how quiet and cautious it is.

The official category keeps it simple: Snake Pokémon.

288 base stat points, with nothing that stands out. Its best stats are 60 Attack and 55 Speed; its worst are 35 HP and 44 Defense. Its 40 Special Attack rules out any plan built around special moves, which matters because Sludge Bomb (level 33, 90 power) and Sludge Wave by TM are among its strongest Poison-type attacks.

Pure Poison typing does not offer much on the offensive side either. When attacking, it only hits Grass and Fairy super effectively, while Steel-types are immune. Defensively, it resists Grass, Fighting, Poison, Bug, and Fairy, in exchange for two very common weaknesses: Ground and Psychic.

What keeps it afloat is Intimidate, which lowers the opposing Pokémon's Attack as soon as Ekans switches in. In Little Cup, the only format where Smogon has analysed it seriously, that ability buys it free switches against physical attackers and, with them, the turn it needs to use Coil. That move, learned at level 44, raises Attack, Defense, and accuracy at once, and the accuracy boost is half the trick: with one Coil boost, Gunk Shot (level 49, 120 power) stops missing. Earthquake by TM takes care of Steel-types. Glare, learned from level 12, spreads paralysis, and Sucker Punch, an Egg Move, finishes off whatever has been weakened.

Outside of that, there is no debate: it neither takes hits nor hits hard enough. Without Coil set up, it threatens nobody, and setting it up with 35 HP depends on getting the switch-in right. In a normal playthrough, its role is that of an early capture that lowers the Attack of anything hitting too hard in the first few Gyms.

Two Egg Groups, Field and Dragon, with the second one being the important one: few Generation I species belong to the Dragon Egg Group, so Ekans serves as a bridge for passing moves into that family without breeding anything expensive. The gender ratio is 50%, so breeding does not depend on finding a rare female or relying on Ditto.

Twenty Egg cycles, or about 5355 steps using (cycles + 1) × 255. The Egg contains six moves that it cannot learn by levelling up. The two worth the effort are Sucker Punch, thanks to its priority, and Switcheroo, for handing the opponent a crippling item. The other four — Poison Fang, Poison Tail, Spite, and Scary Face — have less going for them, and three of them can be taught by TM anyway.

Evolution has no conditions: reach level 22. No items, no friendship, no time of day.

It lives in grasslands and has a 255 catch rate, the top of the scale. It goes down to the first Poké Ball thrown at it, at full health and with no status conditions. It grows at a Medium Fast rate, gives 58 base experience, and yields a single Attack EV, making it a clean opponent to train against without messing up your spread.