Bulbasaur
Bulbasaur is a dual-type Grass/Poison pokemon. It evolves into Ivysaur and Venusaur
Charmander
Charmander is a fire-type pokemon. It evolves into Charmeleon and Charizard
Squirtle
Squirtle is a water-type pokemon. It evolves into Wartotle and Blastoise
Professor Oak
Professor Oak is a Pokemon professor who lives and work at his research lab in Pallet Town.
Grass-type Pokemons
From an attacking perspective, Grass-type attacks are strong against Water-, Rock-, and Ground-type Pokémon and weak against Bug-, Fire-, Flying-, Grass-, Poison-, Dragon-, and Steel-type Pokémon.
Fire-type Pokemons
Fire-type attacks are strong against: Bug, Steel, Grass and Ice-type Pokémon. Fire-type Pokémon are weak to: Ground, Rock and Water-type attacks
Water-type Pokemons
Water-type attacks are strong against: Ground, Rock and Fire-type Pokémon. Water-type Pokémon are weak to: Grass and Electric-type attacks.
Pikachu Not Evolving
Pikachu's refusal to evolve was due to his determination to win and prove himself as a Pikachu, staying true to who he is. Pikachu's decision to not evolve fits the narrative of being great without changing, teaching young viewers an important lesson.
Pokémon is one of the biggest video game franchises in the world so it's no surprise that it has fans everywhere. That includes the world of science where, in 2008, the discovery of a rather unique new protein led to it being named "Pikachurin" after everyone's favorite rodent Pokémon.
