How (Not) to Celebrate the New Year, c. 700

Museum Meermanno, MMW 10 D 7, f. 85v (10th c.)

"If anyone does what many do on the first day of January, that is to say, goes around in the costume of a stag or a calf (which still remains from pagan custom), he must do penance for three years, because this is demoniacal." 

Burgundian Penitential (c. 700)

The first decision of the New Year: do you play it safe, or do you have one awesome day of pagan animal-themed revelry and then do penance until 2017? It's your call.