Walking in grass or a cave will increase your chances of finding a Larvitar.
Try to seek out what is weak against your Larvitar for battles. Larvitar is both a rock- and ground-type Pokémon and is strong against Poison (Koffing), Fire (Vulpix), Bug (Caterpie), Flying (Pidgeot), Electric (Pikachu), Rock (Geodude), and Steel (Aron). Avoid fighting Pokémon that are strong against your Larvitar. Just like the ground-type Pokémon having an advantage over electric-types, your Larvitar also has a weakness against Grass, Bug, and Water Pokémon, like Oddish, Caterpie, and Squirtle. These Pokémon have a higher chance of beating your Larvitar, which will cost you time and life-points. Use potions to help you gain experience quickly. Since you need to battle with Larvitar to level him up, keep potions on hand to heal him or rid him of lingering skills, like Poison Sting, rather than spending time at a Pokémon Center.
You can find rare candies out in the world.
Pupitar levels to Tyranitar at level 55.
