You'll need to trade from Pokemon Emerald.
In order to get Snubbull in Pokemon Fire Red you must do a trade for him. In Pokemon Platinum and Pokemon Diamond Snubbull can be found on Route 209.
You catch Snubbull in Route 37 and 38
Snubbull is a rare Pokemon that can only be found in the Safari Zone extension in Pokemon Emerald.
On Route 38 and 39
In Pokémon HeartGold you can find wild Snubbull at Level 13 in Route 38 additionally you can find it as a Swarming Pokémon in Route 38 but the swarming Snubbull can be found at the minimum level of Level 13 and the maximum level Snubbull of Level 16.
In order to get Snubbull in Pokemon Fire Red you must do a trade for him. In Pokemon Platinum and Pokemon Diamond Snubbull can be found on Route 209.
You catch Snubbull in Route 37 and 38
Only emerald can catch snubbull in the safari zone.
Snubbull is a rare Pokemon that can only be found in the Safari Zone extension in Pokemon Emerald.
On Route 38 and 39
You can catch snubbull at lv.16. You just find Dawn's little sister in her house in Sandgem town and she will tell which Pokemon is swarming. If it is Snubbull then go to the route near Solaceon and Hearthome and find one. And if you can't catch one then you are hopeless.
In Route 38.
In Pokémon HeartGold you can find wild Snubbull at Level 13 in Route 38 additionally you can find it as a Swarming Pokémon in Route 38 but the swarming Snubbull can be found at the minimum level of Level 13 and the maximum level Snubbull of Level 16.
trade granbull (its evouloution) from colloseum, then breed
Snubbull is a Normal type pokemon.
In Pokémon Diamond, Snubbull can be found in the Trophy Garden, which is located behind the Pokémon Mansion in Route 212. It has a low encounter rate, so players may need to spend some time searching to find it. Additionally, Snubbull can be obtained through trading or by transferring from Pokémon games where it is available.
Crunch can only be learnt through leveling up. Before getting the National Dex the only Pokemon you can find that learns it is Nidoran/Nidorina, after that Girafarig, Steelx. Snubbull/Granbull, Houndour/Houndoom, Raikou and Larvitar/Pupitar/Tyranitar.