Saint Killingham is a younger-looking man who possesses a lanky physique and, at least in his partial qilin form, is tall enough to tower over some of his fellow Knights of God, being at least twice the height of Figarland Shamrock. Killingham's Human-Beast Form reveals him to have a dark, messy shock of hair at roughly neck length, slanted eyes with prominent lashes, a well-defined nose, and (at least in his Human-Beast Form) sharp fangs for teeth; if the latter are natural or a trait acquired through his qilin powers is as yet unknown.

As with most Knights of God, Killingham dons an ornate military uniform. It consists of an orange, high-collared, double-breasted tunic with two vertical rows of gold buttons, which extends halfway down his thighs and is matched with a white cravat, beige gloves that reach below his elbows, as well as black pants and orange knee-high, high-heeled boots for lower wear. Over the tunic, Killingham wears a trench coat that is also orange, with epaulets and an armband featuring the Knights of God's emblem on his left upper arm, pockets at waist level, and a black holding it close. Unlike most of the Knights of God seen so far, Killingham has the resin bubble common among lower-rank World Nobles around his head, which is fitted with a respirator in the front featuring two disk filters.