Fopulgorus
Forbes
Ford
Forest Gump
Forever
Formless Spawn
Formosa
Forrest
Forrest Gump
Fortuna
Fos
Fosgate
Foster
Found
Four-By
Four-Legged Reason For Living
Four-Oh-Seven
Fox
Fox "spooky" Mulder
Foxbat (after the animal, not the aircraft)
Foxi
Foxie
Foxx Il Madonna
Foxxy Lucas
Foxy
Foxy Roo
Foxy Roxy
Foxykat
Fozzy (from The Muppets)
Fozzy Bear