What the heck is this thing?!?!?!?!?

I was woken up by this rustling last night. I turn on  my lamp, and saw one my my bags moving! I thought "omg the worst has happened, my room is possessed by a demon!!!"" Oh boy was I wrong.... a few minutes later this HUGE BUG THING crawled out of it!! It was so big I heard it hit the floor. Of course I panicked, and ran out of the room. And then I thought I should catch it so it wouldnt eat me, and in the morning release it back into the wild. So i did, using a contraption I created out of a sandwich box and a spatula. It worked quite well.

I released it this morning, but I am curious; what the heck was it?!?!? And what can I do to make sure it doesnt come back to eat me.