How to Find Heracross in "Pokemon Crystal"by Mitch Reid ; Updated September 22, 2017
While you can find most wild Pokemon scampering through the grass, Heracross is an exception. The beetle Pokemon hides in trees, so the only way to find it is by jostling it from the branches. With high attack power and a unique type combination, Heracross can be a useful addition to your Pokemon team.
Travel to the Ilex Forest, west of Azalea Town.
Navigate to the center of the forest. A man will give you TM02: Headbutt.
Teach Headbutt to one of your Pokemon. Most Fighting-type Pokemon are able to learn this move.
Go to Routes 29 to 33, or Routes 42 to 46.
Use Headbutt on any small trees you see. A Pokemon will fall from the tree.
Repeat Step 5 until you find a Heracross. This may take a few tries; the beetle Pokemon is rare. Once you find Heracross, capture it like you would any other Pokemon.
While using Headbutt on trees, you may also find Spearow, a common Flying-type Pokemon, and Aipom, a Normal-type Pokemon that resembles a monkey.
In battle, Headbutt is a Normal-type move that causes physical damage. Each time you Headbutt a foe, there is a slight chance that the target will flinch, causing it to lose a turn.
At level 44, Heracross can learn Reversal, a Fighting-type attack that causes more damage when the user is low on health. If Heracross uses the attack when its health bar is nearly empty, the move is the most powerful Fighting-type attack in the game.
At level 54, Heracross can learn Megahorn, the strongest Bug-type attack. For a diverse move set, you can also use Technical Machines to teach Heracross attacks such as Earthquake, a Ground-type attack, and Thief, a Dark-type attack.
Heracross’s unique type combination makes it weak to Flying-, Fire- and Psychic-type attacks, but it is partially resistant to Fighting-, Ground-, Bug-, Grass- and Dark-type attacks.
If you defeat Heracross, you will need to continue headbutting trees until another one appears.