Where do you catch an oddish in Pokemon Crystal?

You can find Oddish in two locations in Pokemon Crystal:

1. Route 36 (Day): Oddish is a fairly common encounter here during the day.

2. National Park (Day): Oddish is also found in the National Park, which is accessible after beating the Elite Four. It's a more rare encounter here, but still possible.

Remember, Oddish is a Grass-type Pokemon, so it will only appear in grassy areas during the day. Good luck finding it!