Slurpuff

Slurpuff => is Pokemon dex #685 (not Legendary)

Opendex
=> Pokemon you already have/are registered in your Pokedex, displayed as an image with the Pokemon's details

Non-Opendex
=> Pokemon you don’t have yet/are not registered in your Pokedex, shown as a black silhouette (meaning you’ve seen it in raids/gyms) or just the Pokedex number

Requirements for Trading Opendex:
1. Must have 100 Stardust
2. Must have the Pokemon registered in your Pokedex

Requirements for Trading Non-Opendex:
1. Must have 100 Stardust
2. The Pokemon is still a shadow or you don’t own it yet

Note => Tip for Non-Opendex (Legendary Pokemon/Shiny Pokemon): Be willing to become Ultra Friends to reduce the Stardust cost (80,000 Stardust). If you’re willing, buy the cheapest or your favorite Opendex Pokemon at Wantau Store, then message the seller to request a 30-day friendship (Ultra Friend).

How to Trade Opendex or Non-Opendex? Check the link below: