A two-wheeled transport from the past, To add two more, remove my last. Different beasts can steer my course, But don’t put me before the horse.

At the start of an intro or the end of a line Fish might get caught on it while they dine With a curve and a point it draws them in And in writing it is there to make you listen

Metallic spear, swift and silent, unites and divides in a single twist. Embedded within the mechanical heart, it secures destiny with unwavering precision.

I am your border for privacy, or simply to add scenery. I can be made from many materials, and many old dreams have a white version of me.

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?