Hard to tell by the picture, but looks like Jimson weed to me. Leaves will resemble stinging nettle. I always heard Jimson was poisonous too. A lavender/light blue/whiteish flower on each stalk branch before the pods start developing.
I have one small area by my loafing shed that a plant or 2 comes back from the first year I had one appear and didn't get it cut down or sprayed early.
Inside each of those spiny ball looking seed pods are about 100 little bitty black seeds.You'll have a bumper crop next year. 2,4d will kill it in early growth stage.
other names for it:
It's leaves are a hallucinogenic too.