Firstly a bit of self promotion;
Natural History Notebook is my daily journal of Natural History sightings.
The entries are mainly bullet points and pictures, just to keep a log of what I see and where, but might be interesting and I'd love help IDing things.
Tetrapod Zoology is the blog of Darren Naish, a british Palaeontologist and all round Zoology type, who not only writes about his academic work, but also toy dinosaurs and anything else that takes his fancy. He is also Cryptozoology friendly and has appeared on the British Big Cat episode of Monsterwatch a TV show about cryptids.
The World We Don't Live In is a blog by Emile a student of palaentology at the American University of Beirut. His blog mainly covers dinosaurs, and reptiles, but this allows for such things as speculation on fictional biology and dissecting creationist tracts.
Strange Science is a website that looks at how the fields of Palaeontology and Biology have changed through the use of illustrations from out dated books as well as biography of important biologists. Very interesting and often amusing. Good for day dreams about strange beasties.
Cryptomundo is a cryptozoology blog run by Loren Coleman. it keeps the world right up to date with any kind of cryptozoological news.
WTF nature is a Live journal community dedicated to highlighting natural phenomena that makes you just want to to say ' what the fuck?' or maybe just 'wow' Highlights have been the crustaceans that eat fishes tongues and then lodge themselves in their mouths as an ersatz tongue.
Zooillogix is an animal news blog with mainly light hearted stories.
Messybeast.com is an archive of pictures relating to domestic animals (mainly cats) both historical and current. There are articles on rare and extinct animal and a grea collection of albino and other mutations including hybrids.