I used to have that plant. Then my 1 yo granddaughter tore a piece off and took a bite. She started crying and drooling, I took her to the ER and my boyfriend took the plant to have the state nursery tell us if it was toxic. It is. If you own it, keep it out of a childs reach. She had marks where it was eating the protein in her little mouth. I tossed it.
@prettybrwneyez7757, I would agree that dieffenbachia isn't easy, though it is often said to be. It's on my list of plant divas. Definitely temperamental!