The producers of Riverdale have been hyping up the final episode of Season 1 with that bit Archie Comics debut, which could be referring to a number of characters. For instance, the No. 1 theory is that the character will be Hiram Lodge, the father of Veronica, who has been serving out his own prison sentence this season and aims to factor more heavily into Season 2. Another popular theory more connected to this story is that the highly demanded Sabrina will be the one to finally return to live-action television. In that case, this comic could be foreshadowing her upcoming appearance in the episode. It's that, or the comic serves as her actual "appearance," which would be disappointing.