I have battled players who have had Mew, Mewtwo(NPC), Latias, Darkrai(NPC) Groudon, Ho-oh, Lugia, Entei, Suicune, Raikou, Zapdos, Arceus, Moltres and a couple others.
But how I recieved the CAUGHT data for it and not just question marks across the board? I have no idea.