The first one that came to mind was fli4l (Floppy ISDN for Linux). Originally a distro of German origin that fit on a single floppy disk to turn a 386 or 486 PC into a router for ISDN connections. Last I looked it’s still actively worked on.

There are probably tons of more obsuce ones. But this is one I actually used.

There was a bunch of weird rebadged Ubuntu derivatives back in the day.

Ubuntu satanic edition. https://archiveos.org/ubuntu-satanic/

Ubuntu Christian edition. https://archiveos.org/ubuntu-christian/

Hannah Montana Linux https://hannahmontana.sourceforge.net/