So, there's a man named Ted Cruz and a long time ago someone made a joke that he might be the Zodiac Killer. The Zodiac Killer is a person who did some really bad things a long time ago and nobody knows who he is. But people like to make jokes and say silly things sometimes, even if they aren't true. So, when people talk about Ted Cruz being the Zodiac Killer, it's just a joke and not actually true. It's like when you and your friends make silly jokes with each other just for fun.