you can purchase some from graphic river , or make them in photoshop, or magic voxel, or any other similar software. search google game assets and you will find many thousands.
Men thanks for mentioning MagicaVoxel, I just checked it out and its exactly what I have been looking for
yea magic voxel is good, i use it a lot, then add finishing touches in photoshop. ill find a link and post it, you can download some images already made in magic voxel. If i can find it lol.
@sysads or anyone else that wants them. uploaded some voxel images to drop box for you. just download and drag them into magicavoxel. use them as you like. edit them or just use them. https://www.dropbox.com/sh/949hjseb57lqjug/AABOZJr40RzIEGP7gO3JkkNxa?dl=0 have fun with them. there free no copyright or license blah blah blah. its christmas, time of giving. hope they come in handy for someone.
@sysads On the animal graphics png files, i used photoshop for some facial features, example the monkey, the mouth.
@Machine Rises also brought to our attention these other tools (commercial) Hexels 2 - http://www.marmoset.co/hexels (looks very very very good! ) Qubicle - http://www.minddesk.com/