There's all kind of icon freebies online. I'm not a designer and all these freebies have benefited me greatly. I can just search a little harder to find the design I need. Here we have a delicate set of rare icons to share - 80+ Medical and Science Outline Icon Set Free PSD.
A good collection of icons from PSDfreebies. This icon collection is perfect for medical and scrience related project such as website, brochure, mobile and etc. The best thing is - the icon is vector format, that's mean you can resize it to as large as you need it without affecting the icon resolution. Alternatively, click on this link if you're looking for animal vectors.