The complete Pokemon RBY pokedex, part 12

Pokémon Name: Starmie
Type: Water
Classification: Water/Psychic
Pokédex Number: 121
Ability: Illuminate and Natural Care
Dream World ability: Analytic
Useful Attacks: Confuse Ray
Location Found:
D/P/P/HG/SS: Evolve from Staryu
B/W: Route 13 (via Surf, bubble spots only)

As far as moves go, Starmie's only got one you need to worry about - Confuse Ray, learned at level 28. Everything else comes from Staryu's move set.

Evolution: From Staryu via Water Stone