My kids are balls of pure energy who are offended by the very thought of bedtime. But meditation videos like this one actually keep their interest long enough to help them slow down and begin to relax.
There's a little bit of bait-and-switch in calling this a "video," since it's just a still image with an audio track. But since there's nothing to watch, it's easy to convince kids to close their eyes. The soothing voice invites them to envision the story unfolding in their head. And yes, it even works on my kids.
In this story, you hear a rattle coming from your refrigerator, and discover that inside is a dragon egg about to hatch. After you make the dragon a sandwich, it grows large enough that you can ride it. This might not sound much like meditation, but it gets kids to relax and focus on their own thoughts, which is an age appropriate way to introduce young ones to the concept.
There are tons of other storytime meditation videos (or audio tracks) out there, like this one about a candy castle or this one that takes you on an adventure in space. And technically, you don't have to be a kid to benefit -- they make great bedtime stories for adults, too.
Dragon Story Time Meditation for Kids & Tots [Jason Stephenson Sleep Music]