Does anyone know what these are?

I keep seeing these things on this site. Has anyone else been seeing them too? I'm pretty sure these are ads, but I don't know why they're here specifically, and why they're pretty much everywhere on this site. Does anybody know what's going on?

I have seen those too. And it only shows up on forms not the home page or anything

It is probably add because when you click it you just go to a lot of examples racing game or Mario kart games