Earlier this year, Pokémon GO introduced the mechanic of Raid Battles. These battles feature unusually large and unusually strong Pokémon which players have to work together to defeat. After being defeated, these strong Pokémon, known as Raid Bosses, are reduced to more regular strength and the victorious players are given the opportunity to catch them. Up until now, only a set few kinds of Pokémon have been eligible to be Raid Bosses. Recently, a new set of Raid Bosses have entered the game.
According to ComicBook.com, Pokémon GO has recently introduced new species of Raid Bosses. Many of these new Raid Bosses appear to have replaced previous ones. For example, Ivysaur, Charmeleon and Wartortle are now Level 1 Raid Bosses, replacing the previous Level 1 Raid Bosses Bayleef, Quilava and Croconaw. According to Serebii.net, the current list of Raid Bosses available in the game are as follows:
Level 5 Raid Battles are still reserved for Legendary Pokémon, of which the current ones available are Mewtwo, Raikou, Entei and Suicune, depending on where you live. Previous Raid Bosses that are no longer available include Bayleef, Quilava, Croconaw, Magikarp, Electabuzz, Exeggutor, Magmar, Muk, Weezing, Arcanine, Flareon, Jolteon, Vaporeon, Venusaur, Charizard, Blastoise and Rhydon.