They are depicted in their traditional zoomorphic forms (tetramorph), each holding a name-bearing phylactery.

Thus, the four saints are represented as follows: a winged man for Saint Matthew, an eagle for Saint John, a winged ox for Saint Luke, and a winged lion for Saint Mark.

Mosan region, Phylactery of the Agnus Dei, mid-12th century, oak, copper, gilding, champlevé enamel, engraving, repoussé, stamping, 225 mm x 225 mm x 25 mm. Coll. Fondation Société archéologique de Namur, inv. n°1. (Exhibited at TreM.a, Musée des arts anciens du Namurois).