Does anyone know where I could find an online animal encyclopedia?

Does anyone know of any websites that offer online or downloadable animal encyclopedias? I’m looking for one that’s preferably for adults (no cute little drawings); contains photographs of the animal; lists their localities; states their diet; basically the whole nine yards. When I was younger, I remember owning a binder/book that had all this, but I lost it. And with the huge advancements in technology within the last decade, I’m hoping that I could find something similar, but in digital form. Do we have any zoologists or die-hard animal fanatics here that could help me out? Links are much appreciated :)