In case you haven’t had access to the Internet for the last couple weeks, you may have missed a rash of seemingly sane people dumping buckets of ice water on their heads. Odd, sure, but it’s all in the name of raising awareness and funds for the ALS Association, which helps fund research to find a cure for ALS—also known as Lou Gehrig’s Disease—a fatal, degenerative illness that destroys your body’s motor control. To date, the social media campaign has raised over $40MM. Amazing.

The challenge itself is simple: you make a video of yourself challenging three other people to take the challenge and then you dump a bucket of ice-water on your head. Complete the challenge and you donate $10 bucks to the ALSA, refuse the challenge, donate $100. Up to you.

So what’s this have to do with The Walking Dead? Former show regular Michael Rooker recently took the challenge and then passed it on to Greg Nicotero, Norman Reedus, and the entire TWD cast. Is that more than three people? Yes. Michael Rooker does not care about rules, he cares about wiping ALS off the face of the Earth. Here’s his video:

UPDATE! Apparently Rooker only posted this to his Facebook page, and the YouTube versions are fan rips, which keep getting taken down. CLICK HERE to view on Michael’s page.

To learn more about ALS or to donate, please visit ALSA.org.