Several years ago, for my birthday, my sister gave me a shiny gigantimax toxtricity, one of my favorite Pokemon! It was from a dynamax adventure in Pokemon shield, and she wasn't playing with anybody online, just npcs. I know she hadn't hacked or purchased it, because she showed me a video on her switch of her catching it. (also she was like 7 yo)
It is naturally gigantimax, shiny, and also has perfect spatk ivs, maybe more perfects if I remembered.
What's the combined chance of toxtricity spawning, it being gigantimax, shiny, and perfect spatk?
Thanks in advance!!