Can you eat an avocado seed?
Yes, but they don't taste very good. There are mildly unpleasant chemicals in the pit, but unless someone is allergic, it is unlikely that he would react because it would take eating a lot of them to become ill from the persin and other things in them. Birds can be affected, however, and a number of other animals could be as well. Use the provided link to the Wikipedia article on the avocado and the possibility of a toxic threat, and you can surf on over to see what's up.