The complete Pokemon RBY pokedex, part 1

Pokémon Name: Venusaur
Type: Grass / Poison
Classification: Seed Pokemon
Pokédex Number: 003
Ability: Overgrow – Increases power of Grass-type moves by 1.5 if Pokemon has less than 1/3 HP remaining
Dream World ability: Chlorophyll – Speed doubles during sunny weather
Useful Attacks: Solarbeam
Location Found:
D/P/P: Kanto starter - transfer from FireRed or LeafGreen, evolve from Ivysaur
HG/SS: Evolve from Ivysaur
B/W: Poke Transfer, Evolve from Ivysaur

The flower has bloomed and with it comes the enhanced power and ferocity of Venusaur. It's the only 'saur to learn Petal Dance, a powerful move that eventually confuses the user. As the first final evolution of the franchise, Venusaur sets a precedent that most Pokemon follow - start off cute, then slowly morph into an unsightly beast capable of killing a man, let alone a simple Mantyke.

Evolution: From Ivysaur at 32