What can it be?

On the tip of my foreskin I have like a little ball. Its soft and sqishy can can be moved around. It doesnt hurt and has never gotten bigger. I've had it for as long as I can remember.

When erect its more pronounced as it isn't hidden/tucked into the foreskin. Its on the underside of my penis. I've tried looking on the net and can't seem to find anything about it.