Put the tree and the presents inside a portable playpen. With luck it will keep the cat and other precious and precocious critters { aka Brendan } away from the tree. The cats leave the playpen alone because that noisy, crying, smelly thing that doesn't pet them plays there.

You could also consider this arrangement as an art installation - give it a fancy name like "The Death of Christmas Due To Greed" and sell it after the holidays at an art gallery. We'll let you know what we get for ours.

Merry Christmas Morticia