Let's just jump straight into it
It's this little card on Pyro's board that he has in the background
Idk if you can see it, but it's this little green card with a corgi on it; it's been there as long as he's been doing videos when he stands up. Some of this stuff on the board isn't there before a certain date (I'm guessing he probably acquired it after Insomnia 60 b/c that's when they first appeared), but the card is a constant.