An Uncommon Word?

While I was reading Proba's Cento today, I came across the half-line

facies inmania cete,

which is from Aeneid 5.22. I had to look cete up--it's a neuter plural from the noun cetos (the 'e' is long) and is a direct transliteration of the Greek noun khtos (with 'h' representing eta--sorry, no Greek font), and means 'a sea-monster'. I only have Lewis' Elementary Latin Dictionary in front of me right now, and Vergil is the only classical author cited as having used this noun, which is where Proba got it from, as I mentioned above. Does anyone recall seeing this noun used elsewhere by classical or late antique authors?