1. Lingerie + Animal Ears 

As tempting as it is to spend your whole night quoting Karen Smith’s iconic phrase, “I’m a mouse, duh,” it’s probably time to upgrade the costume you’ve been wearing since “Mean Girls” came out. But if you insist on being something small, furry and suggestive, try dressing up like one of the crazed Penn squirrels. Or you could be the stingray that attacked Steve Irwin.

2. Police Officer, Firefighter, Etc. 

While saying things like “Ooh, underage drinking! Don’t worry, I think I can get you off,” (wink, wink, nudge, nudge) is fun, we recommend you leave impersonating America’s heroes to the pros (and by that we mean strippers and/or pole dancers). A Penn Police Officer or walking escort uniform would be much more fun to make scanty, especially if, while wearing that costume, you then ask for an escort home. Twinz!!

3. Tom Cruise in Risky Business

This costume is perfect in that it is both sneakily lascivious (kind of) AND manages to hide your beer bellies and  food babies. But guys, if you can’t name the song Tom dances to in this scene, you’re going to need to find another excuse to wear your boyfriend’s tighty–whities. We suggest you try being the other famous, barely–clad Thomas of our generation: Tommy Pickles.

4. Sexy Schoolgirl

Judging solely by the prevalence of this costume, one might be led to believe that on our college campuses, pedophilia is, like, sooo totally mainstream! Can we not? If you’re really hankering to wear your tween sister’s skort that you filched over Fall Break, try “sexy librarian” instead: different fantasy, same costume. Or, if you’re just trying to pay tribute to Britney, do a little research first — "Slave 4 U," for instance. Extra points if you incorporate a snake (preferably live).

5. Lax Bro

At least at Penn, the Lax Bro option (costume typically includes pinny tank–top, lacrosse stick, high tube socks, etc.) was invented exclusively to give skinny, nerdy Jewish boys the opportunity to live out unfulfilled fantasies about how life would be if they were their complete opposite: a buff, waspy, inexplicably girl magnet–y idiot. But those pinny’s don’t lie, fellas. The only things you’re going to end up accomplishing are one highly impressive projectile vomit following your failed keg stand and significantly lowered self–esteem amongst all of the girls you try to hit on when they realize their arms are bigger than yours. If you really want to be a waspy athlete, go for a fencing costume — that way no one can see your face or body type!