A cadel is a calligraphic decorative extension to the ascending or descending strokes of letters, usually on the first or last lines of a page. They sometimes feature human or animal heads.
Inicial de cintas; Inicial a pluma
Michelle Brown. Understanding Illuminated Manuscripts (Malibu, CA: J. Paul Getty Museum in association with the British Library, c1994).
Bernhard Bischoff, Latin Palaeography (Cambridge, England; New York: Cambridge University Press, 1990), 229.