Oh, what’s this? Looks like Wooper, the Water Fish Pokémon, is now appearing more often in the wild! https://t.co/bRFA9Ju66n pic.twitter.com/wrz5BRZLHG
— Pokémon GO (@PokemonGoApp) December 11, 2020
In a previously unannounced move by Niantic, Wooper is now spawning en masse in-game, and all reported Team Rocket Grunts for the accompanying Team Rocket Takeover event have been carrying the latest Pokemon to join the Shadow family: Shadow Wooper
It's currently not clear if Wooper spawns/Wooper Rockets will persist throughout the current event, but it's definitely unexpected!