Apion in Harpers Dictionary of Classical Antiquities
A Greek grammarian of the first century A.D., a pupil of Didymus, and president of the philological school at Alexandria. He also worked for a time at Rome under Tiberius and Claudius. A vain, boastful man, he travelled about the Greek cities, giving popular lectures on Homer. Of his many writings we have only fragments left. The glosses on Homer that bear his name are of later origin; on the other hand, the Homeric lexicon of the sophist Apollonius is based on his genuine Homeric glosses. His bitter complaint, Against the Jews, addressed to Caligula at the instance of the Alexandrians, is best known from Iosephus's noble reply to it. See Aul. Gell. v. 14; Epist. 38.
Apion in Wikipedia
Apion (20s BC - c. 45-48 AD), Graeco-Egyptian grammarian, sophist and commentator on Homer, was born at the Siwa Oasis, and flourished in the first half of the 1st century AD.
Apion studied at Alexandria, and headed one of the deputations sent to Caligula (in 40) to attack the Jews with claims of disloyalty following inter communal riots that left many Greeks and Jews dead. Apion's criticisms of Jewish culture and history were replied to by Josephus in Against Apion.
He settled in Rome at an unknown date. Apion taught rhetoric until the reign of Claudius. He wrote several works, none of which has survived. The well-known story "Androclus and the Lion", which is preserved in Aulus Gellius  is from his work: Aegypytiacorum ("Wonders of Egypt"). The surviving fragments of his work are printed the Etymologicum Gudianum, ed. Sturz, 1818.