Scared Shrekless (8pm, NBC) - This animated tale in which Shrek (Mike Myers) gets in the Halloween spirit by challenging friends to come up with scary stories for a contest bumps "30 Rock" out of the NBC lineup tonight. In the cartoon, the gang learn that they'll have to spend the night in Lord Farquaad's haunted castle before a contest winner is named. Cameron Diaz and Antonio Banderas reprise their roles as Princess Fiona and Puss in Boots, but there's no Eddie Murphy. Dean Edwards plays the role of Donkey.

Community (8:30pm, NBC) - The rest of the NBC sitcoms have Halloween episodes tonight. On "Community," a campus Halloween party takes an unusual turn after Pierce and some students ingest a hazardous substance which produces zombie-like symptoms in them. On "The Office," staffers turn overly competitive during a Halloween costume contest (Timothy Olyphant is back). And on "Outsourced," Todd throws a costume party at the office in an attempt to explain Halloween to his Indian coworkers.

Grey's Anatomy (9pm, ABC) - As a TV crew films hospital life six months after the shooting, patient Mary (Mandy Moore) returns for the surgery she was supposed to ahve that day. Also, Cristina has difficulty expressing herself to the crew.

Project Runway (9pm, Lifetime) - The conclusion of the two-part finale reveals the winning designer. Jessica Simpson is the guest judge.

It's Always Sunny in Philadelphia (10pm, FX) - Dee is pregnant and tells the guys that one of them made her that way during a Halloween party that none of them can remember. So they try to piece the evening together "Potemkin"-style, aided by Artemis (Artemis Pebdani) and the McPoyle brothers (Nate Mooney and Jimmi  Simpson).

The Fairy Job Mother (11pm, Lifetime) - A new series in which career specialist Hayley Taylor tries to reshape the lives of families coping with unemployment.