Robert MacCready mentions the character while progressing through the shop floor of Hubris Comics in the Commonwealth. He remarks that the only issue of Grognak the Barbarian he is missing features Skullpocalypse teaming up with Mastadonald to fight Grognak.
- Hubris Comics terminal entries - Letters to the Editor, Feb. 2077
- Robert MacCready: "If I could only find the issue where Mastadonald and Skullpocalypse teamed up to fight Grognak, I'd have a complete set."
(Robert MacCready's dialogue)