Pokemon Scarlet & Violet Teal Mask DLC has brought three new legendaries in the form of Munkidori, Fezandipiti, and Okidogi. While players face them in a tough battle as part of the main story, they are not able to catch at that point, but it is possible later on in the game.
Pokemon Scarlet & Violet DLC: How To Get The Loyal Three Pokemon
The Toxic Trio can be quite formidable foes, so it is quite important to prepare properly for the fight if you want to catch them.