An animated comedy about a family from hell---literally. First up: The devilish Hellmans are sent to Earth and pose as a suburban family in Texas. Their mission: to stop humans from drilling into their hellish realm.

Trying to forge a bond with his boss, Balthazor---with family in tow---mingles at a golf outing at the bigwig's country club. But the Hellmans can't hack it when they fail to fit in.

When daughter Mandy dates the boss' son, Balthazor tries to exploit the blooming romance to inch closer to his boss and the dreaded drill that's burrowing its way to hell.

Various obstacles keep Balthazor and Tina from celebrating their wedding anniversary. Meanwhile, there's bigwig Killbride, who schemes to have a big business initiative approved by exploiting a female EPA exec's interest in Balthazor. Jane Lynch provides the voice of Alex.

Tina's hellish parents visit the Hellmans, but Balthazor goes overboard trying to impress the patriarch. The in-laws worry that Tina and the children will embrace humankind, so they weave a scheme to take the family back to hell.

Balthazor neglects son Josh, upsetting the boy. Meanwhile, a British scientist signs on to work on the dreaded drill, and Killbride conjures up a secret initiative to collect dogs in exchange for guns. Isla Fisher lends her voice.

The oil conglomerate enters the weight-loss market by manufacturing a diet robot that mercilessly abuses the overweight. But when the town falls victim to numerous robberies, Killbride directs the robot to be a neighborhood-watch commander.

Tina must entertain the wife of a Japanese businessman working with Balthazor's boss, but trouble looms due to a personality mix-up, ultimately jeopardizing the Hellmans' mission on Earth.

Killbride reanimates the head of Attila the Hun to help him downsize personnel, but old issues between the historic ruler and Uncle Vlaartark come to light.