@MegaAmphaRime Yup, it's in the let's go games. For the Koffing, I went to the Mansion on Cinnabar Island since it's a nice, open area with high level spawns.
@BL0XYST1NG3R That's not true. Only the next Pokemon of the same species that spawns has the increased shiny rate, otherwise it's back to full odds/odds without the catch combo.