The Peregrinus is not an accidental composition. Rather, the Peregrinus ("Perry") is an aggregation of symbols and an embodiment of legal ideals. Perry’s arched back is said to show the law’s readiness to spring in order to do right and prevent wrong. According to the 1918 Cactus yearbook, the original Peregrinus was “a creature of equity.”
"With his enormous Tail he brushes aside all technicality in favor of Justice, sweet Justice. With the long and pointed Beak he delves deep into the mess of relevant and irrelevant Facts and Fancies, separates the Dough from the chaff and rules out the Collateral. The Irish ditchers boot on his forefoot confesses his membership in the rank and file of the Great Unwashed, alias “The Masses.” The right fore-foot of the he puts foremost, emulating Blackstone’s conundrum “the right foot foremost,” is ensconced in a Stacy-Adams, the boot of civilization—$12.50 a pair—suggestive that old Perry is, and hard as they are, he keeps up with the rapid advance and Ascent of the Times. The two hind feet, boxing-gloved, and each hiding a H. P. Kick are ever prepared to back up the Decrees of law and equity. His Eye is all-seeing and his finely chiseled head is crowed with the Whitecap of Truth."
According to long time Law Librarian Lucy Moore in 1946, Perry boasts the hindquarters of a dog, man’s most faithful friend, and his “broad bill represented the wide latitude of a bill in equity.” While the Peregrinus has changed over time and traded his Irish ditcher’s boot for a cowboy boot, his status as a noble legal emblem remains.