Ok that's just CREEPY!!! Yuck!! I'm afraid of spiders and watching that thing crawl around like that?! I retracts last statement.
Open window, take tank and toss it out said window, go outside and drive over that thing 237 times back and forth to assure its dead, then throw lighter fluid on it and burn it for about 3 hours. Put it out and you should be good.
I'll buy you a new tank, get that beast out of your house!!
"When creating an aqua scape, strive for the beauty of imperfection, as its art and there is no wrong or right, it's left open for interpretation" James Findley