That's a very nice specimen of Philodendron bipinnatifidum or also known as Philodendron selloum. It's an extremely tough plant and can take light to severe pruning.

My friend calls that one "Cujo" for it's untamed growth habit.

Thomas, where it's growing beyond the point where you'd like it to, simply remove whole leaves with their stalks (petioles) all the way back to the main plant. In other words, don't leave stubs.

Thanks everyone!