The character next appeared in "Showcase" #80 in 1969 as a supporting character in the Phantom Stranger story and then as a regular character in the "Phantom Stranger" series that began later that year. Early issues featured a few new pages of story and art that framed reprints of the two characters' old stories. The feature was temporarily replaced by "The Spawn of Frankenstein" in "Phantom Stranger" #23–30, in which Dr. Thirteen appeared, blaming Frankenstein's monster for putting his wife, Maria, in a coma. He made one further appearance in issue #36, replacing the "Black Orchid" serial that had replaced "The Spawn of Frankenstein". He also had a serial in "Ghosts" #95–99 and #101-102. In three of these issues, he confronted the Spectre. He also appeared in "House of Secrets" #150 alongside his longtime rival, the Phantom Stranger.