This phrase is most effective when refering to some asshole (usually a boss, teacher, or other dipshit) who wants to limit your fun. Could be used in the place of Fuck him/her, screw you, fuck off, etc...
My boss said that I couldn't make monkey love to my secretary on his desk, fuck em and feed em fish heads.
*cant play baseball *dont wear sweaters
*not good dancers
*cant talk
*cant play drums
*Don't have to pay to get them in to movies.
*Never seen drinking capucchino in Italian resteraunts with oriental women.
Not frequently seen
Fish heads, fish heads
Rolly polly fish heads
Fish heads, fish heads
eat them up, yumm.
In the morning
laughing happy fish heads
in the eve-eh-ning
floating in the soup