- "Somewhere above him, Hermione whispered, 'Mobiliarbus!' The Christmas tree beside their table rose a few inches off the ground, drifted sideways and landed with a soft thump right in front of their table, hiding them from view."
- —In the Three Broomsticks[src]
Mobiliarbus is a spell that is used to levitate and move a tree. In 1993, Hermione Granger used this spell to transport a Christmas tree over to her table in The Three Broomsticks, to hide Harry Potter, who was in Hogsmeade without permission.
Mobilis is Latin for movable or flexible. Arbor means tree.