My Giant Weed

It's back from last year.  Does anyone out there know what it is. Is something good that happen to come into my yard and just doesn't want to go away even though I don't even water it? Oh well, it's going to be there for a while as I'm just too lazy to dig it out. I wonder how much bigger it will get.

The funny thing is my gardener came by the other day and to trim our bushes and weed whack everything in sight but left this one. I think it so big that he think I'm actually trying grow this plant/weed. 

Only if my other plants did as well with so little care. Here's one more tomato plant picture. I got to show off something that's doing well.