graphicxtras.com > Animal brushes and many examples of the dinosaurs etc
100 Dinosaur brushes for Photoshop / PSP etc Many different creatures are available to buy and use in all your projects, commercial use.
You can find many different sets on the site all with different themes such as hens, cats, horses, frogs and many more. The sets include them in realistic as well as abstract and sketched and rough and much more
100 Dog brushes for Adobe Photoshop / PSP etc Many different pets for use in your projects, commercial