Birthday parties are supposed to be a time for celebration. Usually, a loved one carefully plans out the event to ensure maximum happiness, but sometimes, some unexpected problems pop up. In the movies, that means some sort of bizarre or disastrous shenanigans take place, leading to either hilarity or heartbreak depending on the movie. But whether the outcome leaves you in tears or stitches, the spectacle of a birthday party makes for great cinema, and the seven movie birthday parties on this list are no exception.

"Problem Child." Oh, Junior. What won't you do? A begrudging invitation from a snotty little girl leads Junior, the titular child, to teach the stuck-up brat a lesson. This includes ruining her birthday party at every turn by filling the piñata with decidedly undelicious items and rigging the birthday cake to explode. Simple stuff, but it was definitely effective, and the little girl spent the day crying over her ruined party.

"Harold and Maude." Harold went to great pain to plan a perfect evening for his 80-year-old counterpart in this flick. She'd taught him quite a lot about life, and his respect and appreciation for her was obvious. Sadly, Maude decided to rain on Harold's birthday party plans by no-showing her own party. She had good reason though; she was dead. She'd quietly committed dignified suicide on her 80th birthday, throwing a wrench into Harold's plan.

"The Game." Michael Douglas wasn't bargaining for all of this trouble when he cashed in his birthday gift certificate. But after a wild chase, after his life had been torn apart, Douglas found himself on the roof of the company that had done this to him. Turns out, all of this was an elaborate birthday present from his brother, but Douglas didn't know that until he swan-dived off the roof of the building and fell through a glass ceiling.

"The Birds." Children's birthday parties are about laughter. There are balloons, all kinds of cookies and cakes and fun games for the kids to play. In one California town, there are also ravenous birds that invade the party and eat people's faces. I'm guessing the adults didn't plan on that when they put together this birthday celebration.

"The Omen." The son of a politician is destined for a life of luxury. Everyone is going to roll out the red carpet for the kid, and his birthday parties are going to be the stuff of legend. But for little Damien, his fifth birthday was noteworthy not for its over-the-top pomp and circumstance. No, it stood out because his nanny hanged herself from a building in full view of all the guests and little Damien himself. As far as movie birthdays go, this one was pretty disturbing.

"Harry Potter and The Sorcerer's Stone." Most of the time, movie birthdays don't go as planned because something bad happens, but every once in a while, something great happens instead. Witness Harry Potter's eleventh birthday. His adoptive parents went all out and planned a whole bunch of nothing for Harry's birthday, but then Hagrid showed up. Turns out, Harry is a super-famous wizard. Plus, Hagrid brought cake and stuff. Those two things combined to make Harry's birthday one to remember.

"A.I." The child of two parents is sick, so he's placed into suspended animation. In the meantime, a little robo-kid is ginned up for the parents to love until a cure can be found for their real kid. The real kid is eventually thawed out, but robo-kid sticks around for some reason. On the real kid's eleventh birthday, the robotic sibling tackles him into a pool in order to drown him. Attempted murder by a cyborg? Now that definitely wasn't in the birthday plans.