Nicasius, Quirinus, Scubiculus, and Pientia
Nicasius, Quirinus, Scubiculus, and Pientia were venerated as martyrs and saints. Their feast day is 11 October. Their historicity is uncertain, and "no trustworthy historical reports of [them] exist."
St. Quirinus of Malmedy
The Cathedral of Sts. Peter, Paul and Quirinus, Malmedy
Malmedy (Belgium), Ossuary of Saint Quirin with statue inside Cathedral
A cephalophore is a saint who is generally depicted carrying their own severed head. In Christian art, this was usually meant to signify that the subject in question had been martyred by beheading. Depicting the requisite halo in this circumstance offers a unique challenge for the artist: some put the halo where the head used to be, others have the saint carrying the halo along with the head, and some split the difference.
Associated legends often tell of the saint standing and carrying their own head after the beheading.
Saint Denis of Paris
Saint Denis
St. Denis (second from right) has angelic companions showing him polite concern; portal from Notre Dame de Paris (probably 19th century replacements)
Cephalophore, Cathedral of Reims