Pokedex Entries
Some of the following information is based off of Squirtle's "official" profile and other books from Pokemon, while the rest I have gathered from playing Pokemon. Some information may be based off of the manga version as well if stated other wise.
RED/BLUE: Starter Pokemon from Professor Oak in Pallet Town
YELLOW: Received from Officer Jenny in Vermilion City after receiving the Thunder Badge
GOLD: The shell is soft when it is born. It soon becomes so resilient, prodding fingers will bounce off it.
SILVER: The shell, which hardens soon after it is born, is resilient. If you poke it, it will bounce back out.
CRYSTAL: When it feels threatened, it draws its legs inside its shell and sprays water from its mouth.
RUBY/SAPPHIRE: Squirtle's shell is not merely used for protection. The shell's rounded shape and the grooves on its surface help minimize resistance in water, enabling this Pokemon to swim at high speeds.
EMERALD: Its shell is not just for protection. Its rounded shape and the grooves on its surface minimize resistance in water, enabling Squirtle to swim at high speeds.
FIRERED: When it retracts its long neck into its shell, it squirts out water with vigorous force.
LEAFGREEN: After birth, its back swells and hardens into a shell. Powerfully sprays foam from its mouth.
DIAMOND/PEARL/PLANTINUM: It shelters itself in its shell, then strikes back with spouts of water at every opportunity.
HEARTGOLD: The shell is soft when it is born. It soon becomes so resilient, prodding fingers will bounce off it.
SOULSILVER: The shell, which hardens soon after it is born, is resilient. If you poke it, it will bounce back out.
BLACK/WHITE: It shelters itself in its shell, then strikes back with spouts of water at every opportunity.
BLACK2/WHITE2: It shelters itself in its shell, then strikes back with spouts of water at every opportunity.
X VERSION: It shelters itself in its shell, then strikes back with spouts of water at every opportunity.
Y VERSION: Shoots water at prey while in the water. Withdraws into its shell when in danger
OMEGA RUBY/ALPHA SAPPHIRE: Squirtle's shell is not merely used for protection. The shell's rounded shape and the grooves on its surface help minimize resistance in water, enabling this Pokemon to swim at high speeds.
Where can you get a Squirtle?
RED/BLUE: Starter Pokemon from Professor Oak in Pallet TownYELLOW: Received from Officer Jenny in Vermilion City after receiving the Thunder Badge
GOLD/SILVER/CRYSTAL: The shell is soft when it is born. It soon becomes so resilient, prodding fingers will bounce off it.
RUBY/SAPPHIRE/EMERALD: Event
FIRERED/LEAFGREEN: Starter Pokemon from Professor Oak in Pallet Town
DIAMOND/PEARL/PLANTINUM: Trade
HEARTGOLD/SOULSILVER: Reward from Professor Oak after defeating Red
BLACK/WHITE: Global Link event
BLACK2/WHITE2: Poke Transfer, Event
X VERSION/Y VERSION: Received from Professor Sycamore in Lumiose City after battling him
OMEGA RUBY/ALPHA SAPPHIRE: Trade
You have a 87.5/12.5 % chance of getting a boy over a girl of Squirtle. If you really want a female Squirtle, you will either have to save before you pick your Pokemon in the later games, or just keep replaying the older games until you are given a female. If you are just trying to catch one, I would go with the first one you find because Squirtle is rare to find!