Still a fan

Hi, mushroom expert here.

It's staged in the sense that someone probably took the fan or face off and packed the insides of it with substrate and colonized grain. They then likely replaced the fan and covered the substrate either with a plastic bag or a tote of some kind to function as a humidity tent.

The mushrooms appear to have grown there. But it's a novelty grow of cultivated mushrooms. Rather than mushroom spores landing there and somehow finding enough nutrients and the right conditions to fruit.

I see some strings inside the GPU that may be the mycelium. Also the bottom of the shrooms seem adapted to the space between the fan blades. The question would be what were the mushroom feeding off.

Mushrooms grow up. And some towards the light.

It's probably staged, but I could see this maybe happen if there was a lot of dust caked in between those cooling fins, and then the PC got exposed to water (like in a basement that flooded or something).

Somebody grew mushrooms in a really old gpu while it wasnt in use.