I inadvertently summoned captain planet in the form of a primal Titan in a homebrew 3.5 D&D campaign once. We had five players, each with an artifact level powered item that controlled one of the five elements. Fire, acid, cold, sonic and electricity. Everyone else had items but I was a warforged, a sentient golem essentially so I myself became the embodiment of the element of cold. After we got the last element I had this idea that we all fire our powers at the ground at the same time. We did and the DM gave me this hateful look and rolled some dice. “the ground splits open and a man rises up seemingly made of ice with acid dripping for hair and clothing made of fire wrapped in an aura of crackling electricity.” I laughed uncontrollably for a few minutes while everyone stared at me until I managed to choke out that we had just summoned captain planet. Everyone else joined in and the DM had to look up a picture of him to compare to his description. He was a little embarrassed.