IFA is named after the famous opera singer Ivar F. Andresen who adorns the small candy box.
Ever since the 1930s, his face has been seen on the package, along with a quote recommending the product to "singers, public speakers, smokers and athletes".
Although usually said in it's abbreviated form, sometimes spoken fully.
Meaning you would mount and have sex with literally anything living or non.
Often used as a nonsensical response when you have nothing else to say, lack interest in a conversation or sometimes used to scare others out of conversation so they'll go away.
Person1: What girls are you into?
Person1: You're up against the best player tonight
Person1: What's up?
Person2: I'll fuck anything