I see lots of interesting stuff in my line of work, pest control. Today was one of those days.
I arrived at a client's house and was promptly informed that there was "a really big spider on the front step." Usually when people say "really big" and "spider" in the same sentence, their varying degrees of arachnophobia increase the actual size of the creature by quite a bit in their mind's eye. I put down my spray wand and went to have a look.
Turned out to be a "pregnant" female wolf spider:
That white sack you see attached to her abdomen is specifically how you can know that this is a female wolf spider - other than such obvious clues, identifying the sex of a spider frequently requires such things as microscopes. Inside of the sack are eggs and/or hatched spiderlings. Once they have undergone their first molt, they'll emerge and climb onto their mother's back where they hitch a ride until they're big enough to fend for themselves.
Now, as to her size, to many folks she really is "really big." To people in many parts of the world, they probably wouldn't even take notice of her. In any case, I put a U.S. quarter dollar next to her to establish scale:
She'll now get to live out her days in a nice terrarium, going along with us (the pest control outfit I work for) to home shows and whatnot.