KSP Puppet
KSP kerbal puppet can be found in Skunk storage bay on some landing pads
Cat Mine
There is special tracker mine, stationed inside toroid asteroid in FO. It plays music upon activation and show cat image on explosion.
Retro Posters
Inside the Albion Skunk a poster of an iconic X3: Albion Prelude image is visible on one of the walls of the crew quarters. There are other such posters around the quarters of various different old Egosoft games as well.