- You Look Familiar:
- Mike Cook, who plays Dr. Vincent Edwards, previously appeared as Canoe Cop Gustav in The Monster of Phantom Lake and It Came from Another World!.
- Daniel Sjerven, who plays Stan Johnson, previously appeared as Lt. William Elliot in Cave Women on Mars.
- Stephanie Mihm, who plays Rosemary Bennett, also played The High Priestess of The Zil in Cave Women on Mars.
- Justen Overlander, who played Jonathan in The Monster of Phantom Lake plays Sheriff Elliot.
- Michael Kaiser, who had a cameo as a Martian slave in Cave Women on Mars, appears for the first time as Deputy Hayes.
Trivia / Terror from Beneath the Earth