Beaver Flu is just another name for the Human Immunodeficiency Virus (HIV).
"Man, that trick gave me the beaver flu."
When the party is over and you wake up sick, broke, with nothing left until payday and jones or become irritable.
Don't mind Bob, He's got the bag gone flu.
When you've been on the sniff all weekend causing you to have the sniffles that last more than 2 days
Frank: "boh! Feel more bunged up than Charlie sheen! Sesh flu can fuck clean off
A flu that turns you green and makes your nose grow eventually turning you into an alligator.
"Did you hear that carl has the alligator flu? There's no hope for him!
At least I'll get a new pair of boots from him."
A variety of STDs which could put you on the "bench" until cleared up
"Where's Kim?"
"Oh she went home with that rando and is stuck at home with the cum Flu"
The overall exhausted, eye burning flu like feelings after spending an entire day at a water park
"Hey, are you okay man? You don't look so hot."
"Yeah, I just got the water park flu is all."