Which entity is this text about?

Hippolytus of Rome (170 - 235 AD) was one of the most important 3rd-century theologians in the Christian Church in Rome, where he was probably born. Photios I of Constantinople describes him in his Bibliotheca (cod. 121) as a disciple of Irenaeus, who was said to be a disciple of Polycarp, and from the context of this passage it is supposed that he suggested that Hippolytus so styled himself. However, this assertion is doubtful.

The facts of his life as well as his writing were soon forgotten in the West, perhaps by reason of his criticism of the bishops of Rome and because he wrote in Greek. Pope Damasus I dedicated to him one of his famous epigrams, making him, however, a priest of the Novatianist schism, a view later accepted by Prudentius in the 5th century in his "Passion of St Hippolytus". In the Passionals of the 7th and 8th centuries he is represented as a soldier converted by Saint Lawrence, a legend that long survived in the Roman Breviary. He was also confused with a martyr of the same name who was buried in Portus, of which city he was believed to have been a bishop, who was put to death by drowning in a deep well.  According to Prudentius' account, Hippolytus was dragged to death by wild horses, a striking parallel to the story of the mythological Hippolytus, who was dragged to death by wild horses at Athens. He described the subterranean tomb of the saint and states that he saw there a picture representing Hippolytus' execution. He also confirms August 13 as the date on which a Hippolytus was celebrated but this again refers to the convert of Lawrence, as preserved in the Menaion of the Eastern Orthodox Church.  The latter account led to Hippolytus being considered the patron saint of horses. During the Middle Ages, sick horses were brought to St Ippolyts, Hertfordshire, England, where a church is dedicated to him.
Hippolytus of Rome