Giant Black Widow spider

So here is something that'll give any arachnophobic intruder a real fright. I decided to take a page out of Jabba the Hutt's book, and decided to build a trap door in a room that leads to a ravenous monster below. But instead of a walking potato with teeth, its a giant version of a black widow spider.
Since, she can't actually do anything to intruders. There are webs and spider spawners all along the floor and walls

(note: I had to remove a lot of webs to get a better angle for the pictures.)