Squirtle in FireRed.
Squirtle is a starter in Pokemon FireRed: Professor Oak offers it at level 5 at the start, and it appears nowhere in the wild.
Evolution
3 stages
Squirtle
Wartortle
BlastoiseEvolves into Wartortle at level 16.
Evolve now or wait
from the game's learnsets and the relearner ruleSquirtle evolves at level 16. Nothing is lost by evolving straight away: every move Squirtle learns after that, Wartortle learns too.
Rule the game applies: the Move Relearner on Two Island (he takes two Tiny Mushrooms or one Big Mushroom) teaches only the level-up moves of the form you hand him, at or below its current level. Delaying an evolution costs the evolved form's higher base stats for every level you wait; a move you barely use is not worth that.
Squirtle learnset in FireRed
11 level-up moves · 24 machinesBy level
Wartortle by level
TMs and HMs it can learn (24)
HM03 Surf, HM04 Strength, HM06 Rock Smash, HM07 Waterfall, HM08 Dive, TM01 Focus Punch, TM03 Water Pulse, TM06 Toxic, TM07 Hail, TM10 Hidden Power, TM13 Ice Beam, TM14 Blizzard, TM17 Protect, TM18 Rain Dance, TM21 Frustration, TM23 Iron Tail, TM27 Return, TM28 Dig, TM31 Brick Break, TM32 Double Team, TM42 Facade, TM43 Secret Power, TM44 Rest, TM45 Attract