Gordon Shumway, last known survivor from the planet Melmac, crash-lands his spaceship into the Tanner family's suburban garage. Willie dubs him "ALF", short for Alien Life Form. After convincing a military officer that they are not harboring a space creature, the Tanners decide to take ALF in as a member of the family.

ALF decides to have some fun while a nervous Mrs. Ochmonek baby-sits Brian.

ALF has a crush on Lynn, so he makes a music video to impress her.

ALF sells parts of his spaceship to buy Lynn a Ferrari.

ALF thinks he witnessed a murder at a neighbor's house.

ALF submits scripts to his favorite soap opera.

A cockroach from outer space invades the Tanner home.

When Lucky the cat disappears, everyone pins the blame on ALF.

ALF heads for the garage when Kate's mother pays a visit.

ALF plays matchmaker for Kate's mother.

Willie and ALF both talk to a psychologist.

ALF develops a gambling habit and winds up in trouble with his bookie.

Brian causes trouble at school when he repeats some of ALF's intergalactic knowledge.

When Mr. Ochmonek becomes sick during a flight, ALF flies the plane.

ALF takes a job selling cosmetics over the phone.

ALF befriends a lonely blind girl.

Willie helps homesick ALF arrange a trip to Melmac.

Willie loses his temper with ALF during a family camping trip.

ALF calls the president to address his concerns about nuclear weapons.

On his 45th birthday, Willie feels unfulfilled, so ALF suggests he go skydiving.

It's Christmastime. Unfortunately ALF chops the Christmas tree into firewood before anyone notices. The Tanners then have two tasks: to teach ALF all about Christmas and find a new Christmas tree.

The Tanners continue to try and jog ALF's memory, and deal with the police at the same time.

ALF goes through a 24-hour period of bizarre behavior.

ALF befriends a young Mexican immigrant.

ALF hits his head and is convinced he is an insurance salesman. The Tanners try reviewing past events to try and jog his memory.