Share 'Pet Poisons........ Lets list them!'

I knew a few things that are poisonous to pets, but am finding out more all the time. Who ever knew grapes/raisins were poisonous to dogs!?!?! I thought I heard somewhere that onions were too.... Poinsettias are, right? Chocolate? Just to get the word out there and to learn a bit more for myself, lets see what we can come up with here......