How to unlock Treecko
Treecko is one of the free starters: pick it from the starter selector at the start of a run and it costs no tickets. Later copies come from the Hoenn banner, where it sits in the 1★ pool. The 1★ band takes 45% of all pulls and holds 233 partners, so one specific Treecko works out to about 0.1931% per draw. The 70-pull pity counter only applies to 5★ results, so Treecko has no floor of its own and no targeted pull. A duplicate Treecko refunds 15 coins at the 1★ rate.
Treecko stats and rank
Treecko reads 88 HP, 107 speed, ×1.06 attack, ×0.95 physical, ×1.06 special, 35 defense and 55 special defense, for a 310 base-stat total. On the three-stat percentile this is 28.0 out of 100, which puts Treecko at rank 721 of 966 and in tier C. The relative picture matters more than the total: its strongest slot is speed (54th percentile) and its weakest is defense (5th percentile), so it is a specialist rather than an all-rounder.
Best moves in Treecko's pool
At move level 5 the pool is led by Petal Blizzard at 33.6 damage per 0.26s (137.1 effective DPS, ×1.06 multiplier), then Body Slam at 75.6 damage per 0.71s (100.8 effective DPS, ×0.95 multiplier), then Energy Ball at 38.6 damage per 0.47s (87.9 effective DPS, ×1.06 multiplier). 8 of its 14 damaging moves scale with the physical multiplier and 6 with the special one, alongside 4 support moves. Its special multiplier is the higher of the two (×1.06 against ×0.95), so special moves convert better. The top option beats the second by 36.3 DPS, which decides slot one and leaves slot two as a judgement call. Range, area and knockback are not in the DPS number, so a nova can beat a melee on clear speed despite a smaller figure.
Evolution cards for Treecko
Its starting move, Razor Leaf, evolves into Leaf Storm once the move is at level 5 and you hold the Reflexes card, which boosts cooldown for that run. If Reflexes never appears in that run's level-up offers, the move stays at level 5 and unevolved. 14 of its 18 moves carry an evolution card, across 6 distinct cards (Vigor, Sprint, Power, Reflexes, Armor and Synthesis). The strongest of them is Petal Blizzard at 137.1 effective DPS, so that is the one worth holding a card for first.
Treecko compared to similar partners
The two closest stat lines in the roster are Fennekin (+0 HP, -4 speed, -0.02 attack, -3 total) and Electrike (+0 HP, -2 speed, same attack multiplier, -15 total). Against Fennekin, Treecko is 4 speed faster and Treecko hits harder by ×0.02, and the rank gap is 77 places. Those differences are what you actually trade when swapping partners, not a straight upgrade path, so neither side is a strict upgrade and the move pools have to break the tie.