"The Crystals", reuses a special effect graphic from The Andromeda Strain (1971) to depict an alien blood sample viewed under a microscope.
Mel Blanc returns, with no apparent explanation for the change in Twiki's voice (nor his sudden insistance about Crichton being his "son").
The instrument Wilma uses to look at the crystals is actually an otoscope. An otoscope is used for examining the ear, but are also used to examine the nose and upper throat.
The vocalizations used for the mummy creature are the same as those used for the Hulk in the TV series "The Incredible Hulk"(1977-1982).
The creature costume was reused in The A Team first season episode One More Time.