No vet ever said it was weird ๐คท i got her when she was 12, she's 14 now
It isn't weird, all cats have that
Edit: quick search says it is called a cutaneous marginal pouch
Edit 2: as someone else said, all domestic cats have it (I should have said this from the get go, I have no idea if mountain lions have it. But mountain lions are very beautiful cats. Big paws. Huggable looking. Not advisable to actually hug.)