This is the Pikachu I grew up with and remember. I think it was at some point between 2008 and 2018 that it changed but I can't be certain.. I know for sure it had changed after 2020.
I told my brother about it and he still has a pokemon trading card featuring Pikachu. It was as if the tail had been rubbed so the end of it now looked white. He also remembered the black part of the tail. Upon seeing it white like this he said "That's odd"
I'm fairly sure it was Pikachu's tail that first made me realize something is really off with the reality I thought I knew.. Pikachu's tail was my first Mandela effect as far as I can remember
Since then I've noticed a lot of other things that are really different from what used to be (from my point of view anyway)
Like North America being further west than it used to be, its not South America that moved much but North America, I could tell because I remembered the time zones being different as if it was closer to Europe than it is now
To me this is really real, it happened