ἀθλοφορεύς

From LSJ

κέρκος τῇ ἀλώπεκι μαρτυρεῖ → you can tell a fox by its tail, small traits give the clue to the character of a person

Source

Spanish (DGE)

-ῆος
victorioso de un mártir cristiano RECAM 2.211 (V d.C.).