There is absolutely no need to go into a plot synopsis, you know everything you need to know straight from that title. You either want to watch a movie about a big ass spider, or you don't. For those of us who do, holy shit what a treat. Big Ass Spider simply is what it is, it doesn't take itself seriously in any way. There's a spider on the loose, escaped from the government, and it's growing at an accelerated rate. It's up to the military, with the aid of an exterminator and his sidekick, to put a stop to it before it destroys Los Angeles.
This is the kind of shit I used to write when I was a kid, that's the exact mind frame this movie put me into. It's at times pretty gory, when the spider spits it's acidic venom and melts faces for instance, it has some laughably bad CGI at times but some pretty decent stuff as well, and overall is just a downright hilarious good time. I laughed from start to finish. The cast is lead by Greg Grunberg, who I pretty much only remember as Parkman from Heroes, as the exterminator, and Lombardo Boyar as his trusty, and hilarious, sidekick. These two play off of each other perfectly, and they eat up every scene they're in together. Other notables are first and foremost Ray Wise(!) as Major Braxton Tanner, Lin Shaye, and Clare Kramer. Big Ass Spider also has a pretty hilarious cameo, which I knew nothing about until I saw it, and I won't spoil. You can check IMDB and see who it is, but I recommend just watching the flick and waiting for the scene.
It seems as if these killer animal flicks have run their course as of late, with the exception of the rare gem like Sharknado. Big Ass Spider may end up having something to say about that though. It comes as a hilarious breath of fresh air, and I absolutely loved it. If you dig monster animal flicks, especially the kind that don't take themselves too seriously and just have fun with things, Big Ass Spider is going to be right up your alley. The ending hints at a sequel, and you can bet I'll be first in line for it if/when that happens.