What is the 3rd one in “Dogshit”?

Looks like wojakified GNU, which says it’s an OS on their website.

www.gnu.org

The GNU Operating System and the Free Software Movement

Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share and improve the software they use.

I assume it is GNU Hurd, their own kernel.
GNU Hurd - Wikipedia

Can’t be. One can use the Hurd, and it wont hurt [much]. Not like the corporate enshitified proprietary malware operating systems.