this is a systemzee youtube video, you can even see his youtube logo on the bottom right of the image. He didn't leave a download link but the sniffer + thuff golem + the hide and seek mob + the copper golem + glare + more than 60 other custom mobs, a lot of new biomes a lot of new cosmetics anb furintres blocks can be tested on the origin realms survival server, and it is all free!!!
the ip: play.originrealms.com
the link: originrealms.com