Crazy things. Of course you know that helium gives you chipmunk voice. The others get surprising. I think my favorite is Xenon, “It almost feels like it’s attracted to the ground”.
It should be noted that this is something you should never do as they very likely can kill you if done in excess and done without any thought to safety. This guy seems like he should not be doing them. Especially not with anyone around to help him. But hey, he good for him.