Fighting the Youngster will always result in a Mew encounter because his Slowpoke has a Special of 21 (15 in hex). But if you fight something else before returning to Route 8, it will change which Pokémon you encounter. If you don't know how to catch Mew in Pokemon Red Blue or Yellow see it here on gamezplay.
Let's say you foolishly choose a starting Pokémon other than Bulbasaur and want to make up for it. Bulbasaur's hex number is 99, which converts to 153 in decimal. Now, you could fight a wild Pokémon with a Special of 153, but the only place to find that is on a Level 64 Chansey in the Unknown Dungeon, and those Chansey are quite rare. Worse, they only have a one-in-sixteen chance of having the right Special. Fortunately, there is a solution: Ditto's Transform, which copies the stats of the opponent.
This means that you can catch any Pokémon in the game by following these steps:
- Catch/raise a Pokémon with the proper Special stat (153 for Bulbasaur). You can find a complete list of which decimal value is needed for each Pokémon below.
- Fly away from the Gambler battle.
- Fight any trainer that can see you from a distance and walk up to you. (This is necessary to both unlock your Start button and trigger the Route 8 battle.)
- Find a wild Ditto and let it Transform into your Pokémon with the proper Special.
- Beat the Ditto (or just run away) and immediately fly to Lavender Town without fighting anything else.
- Enter Route 8, and Bulbasaur (or whatever) will appear.
Also note that when you perform this trick, any trainers you fight after the Gambler will be "used up." Make sure you have enough unused trainers to catch all the Pokémon you want!
Fortunately, the Gambler can be used to initiate the trick an unlimited number of times.
Name Hex Dec
---------- --- ---
Bulbasaur 99 153
Ivysaur 09 9
Venusaur 9A 154
Charmander B0 176
Charmeleon B2 178
Charizard B4 180
Squirtle B1 177
Wartortle BC 188
Blastoise 1C 28
Caterpie 7B 123
Metapod 7C 124
Butterfree 7D 125
Weedle 70 112
Kakuna 71 113
Beedrill 72 114
Pidgey 24 36
Pidgeotto 96 150
Pidgeot 97 151
Rattata A5 165
Raticate A6 166
Spearow 05 5
Fearow 23 35
Ekans 6C 108
Arbok 2D 45
Pikachu 54 84
Raichu 55 85
Sandshrew 60 96
Sandslash 61 97
Nidoran(F) 0F 15
Nidorina A8 168
Nidoqueen 10 16
Nidoran(M) 03 3
Nidorino A7 167
Nidoking 07 7
Clefairy 04 4
Clefable 8E 142
Vulpix 52 82
Ninetales 53 83
Jigglypuff 64 100
Wigglytuff 65 101
Zubat 6B 107
Golbat 82 130
Oddish B9 185
Gloom BA 186
Vileplume BB 187
Paras 6D 109
Parasect 2E 46
Venonat 41 65
Venomoth 77 119
Diglett 3B 59
Dugtrio 76 118
Meowth 4D 77
Persian 90 144
Psyduck 2F 47
Golduck 80 128
Mankey 39 57
Primeape 75 117
Growlithe 21 33
Arcanine 14 20
Poliwag 47 71
Poliwhirl 6E 110
Poliwrath 6F 111
Abra 94 148
Kadabra 26 38
Alakazam 95 149
Machop 6A 106
Machoke 29 41
Machamp 7E 126
Bellsprout BC 188
Weepinbell BD 189
Victreebell BE 190
Tentacool 18 24
Tentacruel 9B 155
Geodude A9 169
Graveler 27 39
Golem 31 49
Ponyta A3 163
Rapidash A4 164
Slowpoke 25 37
Slowbro 08 8
Magnemite AD 173
Magneton 36 54
Farfetch'd 40 64
Doduo 46 70
Dodrio 74 116
Seel 3A 58
Dewgong 78 120
Grimer 0D 13
Muk 88 136
Shellder 17 23
Cloyster 8B 139
Gastly 19 25
Haunter 93 147
Gengar 0E 14
Onix 22 34
Drowzee 30 48
Hypno 81 129
Krabby 4E 78
Kingler 8A 138
Voltorb 06 6
Electrode 8D 141
Exeggcute 0C 12
Exeggutor 0A 10
Cubone 11 17
Marowak 91 145
Hitmonlee 2B 43
Hitmonchan 2C 44
Lickitung 0B 11
Koffing 37 55
Weezing 8F 143
Rhyhorn 12 18
Rhydon 01 1
Chansey 28 40
Tangela 1E 30
Kangaskhan 02 2
Horsea 5C 92
Seadra 5D 93
Goldeen 9D 157
Seaking 9E 158
Staryu 1B 27
Starmie 98 152
Mr. Mime 2A 42
Scyther 1A 26
Jynx 48 72
Electabuzz 35 53
Magmar 33 51
Pinsir 1D 29
Tauros 3C 60
Magikarp 85 133
Gyarados 16 22
Lapras 13 19
Ditto 4C 76
Eevee 66 102
Vaporeon 69 105
Jolteon 68 104
Flareon 67 103
Porygon AA 170
Omanyte 62 98
Omastar 63 99
Kabuto 5A 90
Kabutops 5B 91
Aerodactyl AB 171
Snorlax 84 132
Articuno 4A 74
Zapdos 4B 75
Moltres 49 73
Dratini 58 88
Dragonair 59 89
Dragonite 42 66
Mewtwo 83 131
Mew 15 21
