This is Amanita sp., but I I cant be more precise, its hard to choose from variety of certain species, they all look the same for me, and I not a mycologist to see the minimal distinctive touches.

the pot was located indoors, right?and mushrooms decided it has a suitable environment to pop-up, all of a sudden. thats amazing case, indeed!

!PIZZA - and welcome with your 1st post to FL. you know, we have a #fungifriday fun challenge, my friend.