Zubat was one of the original 151 Pokemon of the first generation of "Pokemon" video games. In the original "Red" and "Blue" versions of "Pokemon," Zubat evolved into Golbat at level 22. In the second generation, which featured "Gold" and "Silver," Golbat was able to make another evolution into the newly introduced Crobat. Making Zubat evolve into Crobat requires the inevitable middle step of Golbat.
Acquire a Zubat. You can find Zubats on just about every corner of the "Pokemon" globe, including Johto routes 3, 4, 10, 30, 31, 32, 33 and 42. Zubat is also abundant in Kanto locations such as Mt. Moon, Rock Tunnel, Seafoam Islands and Victory Road. Carry some basic Poke Balls, Great Balls or Fast Balls to catch it.
Level up your Zubat. Your little winged Pokemon friend will be weak at first, knowing only simple moves such as Leech Life and Supersonic. Put him in frequent battles with types he does well against, such as Bug-, Grass- and Fighting-types. When he reaches level 22, your Zubat will evolve into a Golbat.
Make your Golbat happy. Golbat is one of those rare Pokemon that do not evolve by merely reaching a specific level; a Golbat will only evolve if he is sufficiently happy. Happiness is a value between zero and 255. Pokemon automatically have a happiness of 70 once caught or traded. Gaining a level adds 2 to 5 happiness points, using vitamins adds 2 to 5 points and grooming adds 1 to 10 points, depending on who is the groomer. On the other hand, fainting loses 1 happiness point, using Heal and Energy powders loses 5 points and using Revival Herbs loses 15 points. Once your Gobalt's happiness score is high enough, he will evolve into a Crobat.
Give your Zubat the Exp. Share item to enable him to gain experience points from battles in which he doesn't participate. This way, he can continue gaining points even when he is too weak to fight. In "Pokemon Gold" and "Silver," you can get the item from Mr. Pokemon. A high level of happiness is often considered 200 or higher, but no information has been revealed as to the exact point at which Golbat evolves.