Pictures depicting sex between humans and animals are illegal in the USA and many other countries. Most countries view this material as being similar in nature to child pornography, and as such are very strict about prosecuting those who have such material. No such files will appear on the UZP, nor will I send any image files, photos, or videos to anyone. To find this material on the net, you might try these newsgroups:

alt.binaries.pictures.erotica.animal
alt.binaries.pictures.erotica.animals
alt.binaries.pictures.erotica.bestiality
alt.binaries.pictures.tasteless
alt.sex.bestiality.pictures
alt.tasteless.pictures

Be advised that if you read these newsgroups, you do so at your own risk--you never know who's working for whom. Be careful out there.