I didnt create anything like that even once (though I would like to!)

I bet there used a few two point light sources (LEDs) placed behind the mushrooms at close range. well, and a good camera of course.

if you google image search using 'mushroom + led' keywords.... I am sure you will be delighted!

(this one is not a real mushroom, but anyway).

look here: these are real photos, and real mushrooms. pure magic, indeed!