Here's why:
* TMs are different: In Pokemon Crystal, Waterfall is not a TM (Technical Machine) that you can find or buy.
* HM07: Waterfall is an HM (Hidden Machine) and specifically HM07.
* Learn it from a Pokemon: You need to teach a compatible Pokemon the Waterfall move.
How to get Waterfall in Pokemon Crystal:
1. Get HM07: You'll find HM07 in the Ilex Forest, inside the house with the two trainers.
2. Find a compatible Pokemon: Not all Pokemon can learn Waterfall. Some common choices include:
* Squirtle line: Wartortle and Blastoise
* Totodile line: Croconaw and Feraligatr
* Gyarados: This is a powerful Water-type Pokemon that evolves from Magikarp.
* Kingdra: A strong Dragon/Water-type Pokemon that evolves from Seadra.
3. Teach it to your Pokemon: Go to a Pokemon Center and talk to the person with the "Teach HM" option.
4. Use it: Now your Pokemon can use Waterfall to navigate waterfalls and reach new areas in the game.
Important Notes:
* HM07 is a limited-use move: This means you can only use Waterfall a certain number of times before you'll need to re-teach it.
* Some areas are only accessible with Waterfall: This makes it a vital move for completing the game.
Good luck finding Waterfall and exploring the world of Pokemon Crystal!