My penis has a mole on the head ,is that a good thing?

You do know, don't you, that you could be prosecuted for animal cruelty?

Moles aren't usually good things in general. If it gets bigger than a pencil's eraser, get it checked out. You might have to get it surgically removed so it doesn't develop into something new, but if it's tiny, it shouldn't be too big a problem.

if it bothers you see a doctor

that is not normal, see skin diseases