The ALS Ice Bucket Challenge works like this: someone challenges you; you then either donate $100 to fight Lou Gehrig's Disease, or you dump a bucket of ice water on your head and donate some smaller amount of money; either way, you give them money.
Some people really hate the whole thing, which is understandable: it's ridiculous, and for a lot of participants, it's more about getting attention for themselves than for ALS. But it's absolutely doing its job in raising awareness - and also in raising money! So far they've raised more than $30 million, which is nothing to sneeze at (after you catch a cold from dumping ice water on yourself). And if you've used a "Keep Calm" meme or watched a Harlem Shake video, you have no excuse for hating this.
It's still a horrible idea for Gizmo to accept Zan's challenge, since mogwais can't get wet. And obviously his decision-making skills are pretty bad, because otherwise he wouldn't have challenged 1) a man prone to rusting, 2) an electric-themed supervillain, and 3) someone who changes gender when they get wet. Use your brain, Gizmo!