1. Find a Caterpie: Caterpie can be found in various grassy areas, most commonly in the following locations:
* Route 2: Between Cherrygrove City and Violet City.
* Route 30: Just outside of Goldenrod City.
2. Evolve Caterpie: Caterpie will evolve into Metapod at level 7. Metapod evolves into Butterfree at level 10.
3. Teach Sleep Powder: Butterfree learns Sleep Powder naturally at level 28.
Important Note: This isn't a special "Pink Butterfly" with a unique appearance. It's simply a regular Butterfree with the move Sleep Powder.
Additional Information:
* Shiny Butterfree: If you're looking for a shiny Butterfree, it's a rare occurrence. You'll need a lot of patience and luck to encounter one in the wild.
* Trade: You can always trade with other players to get a Butterfree with Sleep Powder, or even a shiny one.
Let me know if you have any other questions!