It appeared in one of the cartoons though let's face it. Its ridiculous to know this is the first hint of X-Men in the MCU. Remember the first hint of X-Men on the big screen? Magneto was a prisoner in 1944 concentration camps in Hitler's Germany. Am sure, Sharks and dropping X-Men's name in a comedy movie like Thor 4 will get the same kind of critical praise and fans applause. lol.