has anyone seen this tail in a cat?

my cat has always had a curly tail like in the photos. his tail is like this ALL the time. it’s never straight. i’ve taken him to the vet before about other things and they’ve never said anything about his tail so im assuming it isn’t serious. he isn’t pain. he just goes about his day. i’m just curious as i’ve had many cats before and ive never seen this!

he’s just a normal domestic cat.