Several kinds of living creatures are used as Christmas ornaments as well as many inanimate objects, including:
Bubbles, everlasting candles, everlasting icicles, and enchanted snow.
Wizards use real, live fairies as fairy lights. Flitwick once decorated his classroom with them (PA10) and the garden was decorated with them for the Yule Ball (GF23). According to Fleur, choirs of wood nymphs serenade the students as they eat in the Dining Chamber at the Palace of Beauxbatons at Christmastime (GF23). Ornaments on Christmas trees can include luminous holly berries and "real, hooting, golden owls" (GF23).