Bloody Birthday is a 1981 slasher horror film about three sociopathic children, Debbie, Curtis, and Steven, born under an eclipse as foretold that anyone born under an eclipse of Saturn would have a personality flaw. Joyce Russel and her brother Timmy must work together to stop their murderous rampage.
Tropes featured in this film include:
- Adults Are Useless: Apparently, everybody above the age of twelve carries the Idiot Ball at all times.
- Ax-Crazy: All three children, Curtis in particular.
- Batter Up!: Steven beats Debbie's father Sheriff Brodie to death with a baseball bat.
- Bedsheet Ghost: Steven's disguise while trying to run Joyce down in the junkyard combines this with a touch of Sackhead Slasher.
- Cassandra Truth: Nobody believes Joyce and Timmy that Debbie, Curtis, and Steven are killers.
- Creepy Child: The three main children when they're not trying to be cute.
- Creepy Clown: The birthday clown wearing an "I Can't Say No" T-shirt. He doesn't do anything other than juggle at the party, though.
- Dirty Kid: Curtis is quite perverted for someone who's only ten years old.
- Disproportionate Retribution: They murder their teacher Ms. Davis because she won't allow them a day off from homework for their birthday parties.
- Enfant Terrible: The three children were sociopaths from birth.
- Eye Scream: Beverly gets an arrow through the eye from her psychotic younger sister Debbie.
- Final Girl: Joyce, the wholesome teenager who along with her young brother is the last to confront the killers.
- Flat Character: Steven gets the least amount of characterization.
- Karma Houdini: Curtis and Steven are arrested while Debbie escapes with her mother under a new identity so she can continue to murder.
- Lack of Empathy: The three murderous kids were born during an eclipse of Saturn, which removed all of their emotions.
- More Deadly Than the Male: Debbie is the leader and the only one who manages to evade capture in the end.
- Ms. Fanservice: MTV's Julie Brown. (No, not Downtown Julie, the other one.)
- Nerd Glasses: Curtis, who is one of the most intelligent children in the film, wears a pair of these.
- No Honor Among Thieves: Debbie betrays her partners in the end.
- Tampering with Food and Drink: Curtis may or may not have poisoned cake frosting, but Joyce catches him with poison in hand and makes a scene at the birthday party to stop anyone from consuming possible bad cake... just as Curtis planned.
- Too Dumb to Live: Even though she knew about the peephole Debbie set up, Beverly never thinks to cover it up, which results in her death.
- Wounded Gazelle Gambit: Curtis abuses this when Joyce tries to uncover their crimes.
