We are currently in a time of abundance when it comes to free game development resources, and Quaternius is a prime example of this. With thousands of 3D assets that are often game-ready, rigged, and animated, this site offers a wide range of genres and themes. Similar to asset packs from Kenney.nl, Quaternius releases its assets under the CC0 open source license, which allows for liberal usage rights.
Not only does Quaternius offer a variety of free 3D assets, but it also provides several single-page animated tutorials, much like those found on Lospec (another excellent free art resource). All assets can be downloaded from Google Drive, but if you support the site through Patreon, you can access a single file download that includes them all.
Below, you can find a video that provides information about the free assets offered on Quaternius.