In The Garden: Please help in identifying this plant

Hi guys, just wondering if anyone may now what type of plant this is? I dug my small garden out of sod, so a bit surprised by the size if this plant if it turns out to be a weed. I also had a random sunflower grow, but not surprised as I have a bird feeder and the seeds get everywhere. Thanks!

 

Amaranthus. It'll be from the bird seed; might as well keep it for a free new bird seed supply ;-)

 

Thanks!!! :)