That gnarly plant is known as a Hercules Club. Right now I'm not sure if it's a weed that will become a plant (after all, a weed is just a plant in the wrong place) or if it's a weed that shall remain a weed and go to that place where all weeds should go.
If it's to become a plant, I really need to move it and move it soon! This baby can grow to 25 feet of thorny trunked treeness in a matter of minutes months. The plus is that giant swallowtail butterflies consider it a great place to lay their eggs and the minus is, well, fairly obvious.