Is this dangerous
The image is a little blurry, but the caterpillar looks a lot like it could be the catalpa sphinx moth. If they have a short, pointed tail then it is almost certainly that species. The catalpa sphinx moth occasionally has big population years, it might go unnoticed for many years in a row when at low populations. It has a few highly effective natural enemies that will generally knock the numbers down rapidly.
The adults are a dull brown/gray moth, sometimes as big as 3 inches in wingspan.
I forgot to answer your lead question--is this dangerous? No, they are harmless to people. If there are lots of the caterpillars roaming over the ground (once they are done feeding on the catalpas they dig underground to form their pupal stage) then dogs sometimes eat too many of them and get an upset stomach.
Thanks so much. I have a cut down tree that was on my property when I bought it but every year it sprouts these tall bamboo-like branches with huge leaves which are very pretty then I cut them all off in the fall and the cycle repeats. A couple of days ago I glanced out a window and the leaves were covered in the caterpillars and by the next day they were totally eaten up. I’ve bee here for 14 years and this is the first time so I was a little concerned especially when I saw some on other plants. Now I know it’s a catalpa !
Insects can certainly surprise us. Glad to be of help.