Mr. Mime. Walk through Digletts Cave to route 2. As you come out youll see a little house. Go to the first house there and talk to the guy in the back and trade an Abra for Mr. Mime.
Jynx. Go to Cerulean City and go in the house next door to the pokemon center and trade a Poliwhirl for a Jynx.
Farfetch'd. Go to Vermilion and find the second row of houses. Go in the first house on the end and trade your spearow of Farfetch'd.
Electrode. Go to the lab on Cinnabar Island. Go in the lab and the first door inside. Talk to the guy standing up and he'll trade you Raichu for Electrode.
Tangala. Go to the same place to where you trade Raichu and talk to the lady sitting and trade Venonat for Tangala.
Eevee. Go in Celadon mansion through the back and go up to the top. There is a pokeball and it is Eevee.
TM 32, 33, and 07. You can get theseTM's in the big mart in Celadon City. TM 32 is Double Team. TM 33 is Reflect. Tm 07 is Horndrill.
Mewtwo. You do not need a masterball. Go to the Unknown Dungeon. Go to the basement and there will be Mewtwo.
When you catch all 150 Pokemon the game designer gives you a diploma.