Creepshow S02 E04 Pipe Screams / Within the Walls of Madness

"The Most Fun You'll Ever Have Being Scared."

A drain clog turns out to be more than just a little matted hair and soap scum, and a down-on-his luck plumber is tasked with getting the problem under control. Trouble is, the problem has a mind of its own. Then, a top-secret government compound is evacuated as the last few scientists in the building fight to contain the creature they’ve been studying- but is the true threat one of them?