Flint (tup, twin) - a form of sedentary rock
Fossil (tup, twin) - preserved remains of a once-living thing from a past geological age
Fornus (tup, twin) - Roman god of flocks
Faustitas (ewe, twin) - Roman goddess of flocks
Fagus (tup, twin) - the genus of beech trees
Foxglove (ewe, twin) - wildflower
Fern (ewe, twin) - found in the woodland
Fleming (tup, twin) - Alexander; discoverer of penicillin
Funi (ewe, twin) - Old Icelandic word meaning 'fire' or 'blaze'
Fafnir (tup, twin) - Norse mythological dwarf who turned into a dragon
Faraday (tup, twin) - Michael; famous physicist
Farenheit (tup, twin) - Daniel; famous physicist
Fairfax (ewe, twin) - the housekeeper at Thornfield Hall in the novel Jane Eyre by Charlotte Brontë (her mother is Brontë)
Ford (tup, twin) - Prefect; character in Douglas Adams' "Hitchhikers Guide to the Galaxy" series
Florence (ewe, twin) - Nightingale; famous nurse
Francis (tup, twin) - Drake; English explorer and privateer
Fuchsia (ewe, single) - flower
Fescue (ewe, twin) - type of grass
Feverfew (ewe, twin) - wildflower
Feynman (tup, twin) - Richard; famous physicist
Flax (ewe, twin) - wildflower
Frodo (tup, single) - character from JRR Tolkein's "Lord of the Rings" trilogy
Fornax (tup, twin) - constellation in the southern celestial hemisphere; Latin for furnace
Fawaris (tup, twin) - a blue giant star located about 165 light years away in the constellation Cygnus
Freud (tup, twin) - Sigmund; famous psychologist
Franklin (ewe, twin) - Rosamund; famous British chemist and X-ray crystallographer
Forget-me-not (ewe, twin) - wildflower
Fritillary (ewe, twin) - wildflower
Får (ewe, single) - Danish/Swedish for sheep
Faramir (tup, twin) - character from JRR Tolkein's "Lord of the Rings" trilogy
Fett (tup, twin) - Boba; character from the "Star Wars" films
Fama (ewe, twin) - the personification of popular rumour in Greek mythology
Fate (ewe, twin) - one of three Greek goddesses who determined human destinies, and in particular the span of a person’s life and his allotment of misery and suffering
Frost (ewe, twin) - a thin layer of ice on a solid surface
Fractus (ewe, twin) - clouds in the form of irregular rags with a distinctly jagged appearance
Freyja (ewe, twin) - a goddess from Norse paganism associated with love, beauty, fertility, magic for seeing and influencing the future; rules over her heavenly field; twin of Freyr
Freyr (tup, twin) - a god from Norse paganism associated with fertility, prosperity, fair weather and good harvest; twin of Freyja
Fauna (ewe, twin) - all animals
Flora (ewe, twin) - all plants
Fox (tup, single) - Mulder; character from "The X-Files" TV series