Do Manx cats use body wiggles instead of tail flicks to show mood?

That's a great observation. Since Manx cats don't have a full tail to flick, they definitely rely more on body wiggles and other movements to express themselves. I've seen many Manx cats use a subtle rear-end wiggle or a full-body ripple when they're excited or about to pounce-similar to how a tail might twitch before a hunt. They also use ear positions, eye blinks, and even their back feet to communicate. So yes, body wiggles become a key part of their mood vocabulary, but it's not a straight swap. You have to watch the whole cat.