Folfanga is a star system, the fourth planet of which is inhabited by a species of small slug, of the genus A-Rth-Urp-Hil-Ipdenu. Wowbagger, the Infinitely Prolonged travelled to this planet (immediately after his encounter with Arthur Philip Dent) to insult one such slug, intending to call it a "brainless prat". Folfangan slugs judge a number's worth based on the artistic integrity of its shape. Consequently, the Folfangan economy collapses at least once a week.
Folfanga is mentioned in:
- The Douglas Adams book Life, the Universe and Everything.
- The Eoin Colfer book And Another Thing....