for Christmas, but not for your pets.
1. Poinsettia - Beautiful, yes. Usually not deadly. Sap can act as an irritant and the plant itself can cause vomiting.
2. Mistletoe - Deadliness depends on the amount of berries that were eaten. Usually GI upset and all that goes along with it, but extreme cases can result in shock.
3. Holly - Small amount of berries, probably ok. But not always depends on the amount eaten. Causes vomiting and diarrhea that can lead to an electrolyte imbalance.
All of these plants have the potential to be hazardous, so don't take a chance and make sure that they are out of your pets reach. For detailed information go to this article on Toxic Christmas Plants.
Or if you are like me and have dogs that find a way into everything, go with plastic instead!