Sounds like you scored there bro,
I love dirt, things seem so much better with good loamy dirt, love the smell of it. I would carefully examine under all the leaves and in every nook and cranny. Move around some of the soil a little and see if you might stir up the critter assuming that he has a wee bit of a hiding spot in the soil, you never know with the millions of different bugs ya know?
check all around the container, and remove the spider as many spiders put droplets on their web strands that are designed to act as dissolving enzymes.
Hope you find the little bugger, and when you do remember eye for eye tooth for tooth, LOL
smoke in peace
KingKahuuna