Gordon "ALF" Shumway
The lovable main character of the show.
- Adorkable: When he tries to help the family or understand Earth culture.
- Advice Backfire: What usually causes his problems in most episodes.
- Aliens Are Bastards: Whenever he acts aggressive.
- Aliens Speaking English: His entire species has a good grasp of English.
- Amusing Alien: Why the audience loves him so much.
- Annoying Laugh: Haaaa!
- Anti-Hero: He has aggressive and rude moments.
- Ass in Ambassador: In Project Alf he becomes the representative of Melmac.
- Beware the Nice Ones: Threaten his family and he'll threaten you.
- Big Eater: He does have eight stomachs to fill.
- Bizarre Alien Biology: His species have 10 vital organs. Eight of which are stomachs.
- Brilliant, but Lazy: He was formerly the captain for the Bouillabiasseball team back on Melmac.
- Butt Monkey: At times. Usually it's from his own mistakes.
- Catchphrase: Haaaa! I kill me.
- Cloudcuckoolander: By Earth standards he comes across as his.
- The Cloudcuckoolander Was Right: However, he does have his moments where he is smart.
- Covert Pervert: Knows a lot about human anatomy than he lets on.
- Deadpan Snarker: The majority of his jokes come from this trait.
- The Dog Is an Alien: One time he pretended to be a dog in order to fool humans.
- Earn Your Happy Ending: In Project Alf he avoids being killed by the Big Bad, becomes the representative of Melmac, and gains acceptance from humanity.
- Good Is Dumb: He might be the Trope Codifier for this.
- Hidden Depths: He's a very talented musician.
- Hypocrite: Claims that he is fully capable of cleaning up his own messes then relies on the family to help bail him out of trouble.
- Idiot Hero: He does more bad than good throughout the entire series.
- I Just Want to Have Friends: One of the main reasons he's forgiven by his actions.
- I Want My Beloved to Be Happy: Feels this way about Lynn.
- Innocently Insensitive: He often insults people accidentally.
- It's All About Me: Sometimes he only worries about himself too much.
- Jerk with a Heart of Gold: He can be a real jerk, but he does love his family.
- Karma Houdini: Sometimes he doesn't get punished for his mischief.
- Kick the Dog: More like "kick the cat". He casually reminisces about his cat kills.
- Kindhearted Cat Lover: Overcomes his hate against cats after adopting a Cute Kitten.
- To be fair, like all Melmacians he always loved cats... well cooked, with a nice side dish.
- Last of His Kind: Subverted. He is believed to be the last of his species until it's revealed that other Melmacians escaped the explosion.
- Lazy Bum: Does nothing to help out the family. Justified since he is an alien, but that's no excuse since he creates messes at their home.
- Lovable Coward: He has a tough time handling his problems and hides behind his family.
- Made of Iron: Survived a space crash, a car crash, and a kitchen explosion.
- Manchild: He's over 400 years old and still behaves like a 5 year old.
- Nice Job Breaking It, Hero!: Most of the time he causes the problems of the show. He even screws up when he tries helping his family out of easy problems.
- Pet the Dog: He occasionally looks out for his family and does come through when they need him.
- Small Name, Big Ego: Apparently, he was known as Mr. Science back on his planet.
- Smug Snake: Can be selfish at times.
- Snark-to-Snark Combat: Has a moment with everyone.
- Too Dumb to Live: It's amazing he's even alive after all the crap he's pulled.
- Took a Level in Badass: He fought off a giant cockroach in La Cucaracha.
- Took a Level in Jerkass: In the last season.
- Took a Level in Kindness: Started out hating humans and condescending towards Earth concepts, but grew to accept and appreciate it over time.
- Ungrateful Bastard: Subverted. He comes across as this a lot of times, but he really is grateful to the Tanner's for saving his life.
- Unsympathetic Comedy Protagonist: He is usually sympathetic, but sometimes he doesn't apologize.
William "Willie" Francis Tanner
- Beware the Nice Ones: When pissed off he can get very intimidating.
- Butt Monkey: Usually the one who suffers from Alf's mischief.
- The Chew Toy: Is constantly annoyed by Alf.
- Deadpan Snarker: What makes his character funny.
- Good Parents: With Kate.
- Happily Married: With Kate.
- Jerk with a Heart of Gold: He's only this towards Alf.
- Large Ham: ALF! What you did was WRONG! WRRROONNNNG!...wrong.
- "You're STALLLLLLLLLLLLLL-ing!
- Only Sane Man: Compared to Alf and everyone around him, he's the only one to think rationally.
- Tranquil Fury: He tries his best to hold back against Alf. And that's saying something.
- Ugly Guy, Hot Wife: The ugly guy to Kate's hot wife.
Kate Daphne Tanner
- Deadpan Snarker: Always delivers at least one sarcastic quip per episode.
- Fiery Redhead: When she gets in an angry mood.
- Good Parents: With Willie.
- Happily Married: Again, with Willie.
- Jerk with a Heart of Gold: She's sometimes this way towards Alf.
- Ugly Guy, Hot Wife: The hot wife to Willie's ugly guy.
- Adorkable: She tries to keep the family together, but ends up making herself embarrassed.
- Butt Monkey: She has her moments.
- Deadpan Snarker: As expected of a teenage daughter character.
- '80s Hair: Her style is outdated by today's standards.
- Plucky Girl: Always the optimist of the family.
- Shrinking Violet: She lacks confidence in herself too often.
- The Ugly Guy's Hot Daughter: The hot daughter to Willie's ugly guy.
- Cheerful Child: His defining characteristic.
- Flat Character: Receives the least character development out of every character.
- Morality Pet: For Alf.
- Nice Guy: Treats Alf with respect.
- Character Death: In the episode, "Live and Let Die".
- The Chew Toy: Alf's literally trying to chew him up, but always fails.
- Nice Kitty: Never acts up, even against Alf.
- That Poor Cat: Always chased by Alf.
Mrs. Raquel Ochmonek
- Evil Old Folks: Averted. She isn't really evil, just really annoying.
- Nosy Neighbor: Her defining characteristic.
Mr. Trevor Ochmonek
- Drop-In Character: His main role.
Dorothy Halligan Deaver
- The Bully: To ALF.
- Jerk with a Heart of Gold: She is very rude to ALF, but she loves her daughter and her family.
- My Beloved Smother: In her debut episode she takes over Kate's life. She grows out of this thanks to Alf.
- Widow Woman: Lost her first husband before the start of the series.