At times, the cover head would replace Sonic with another significant character from that issue, early examples being Shortfuse the Cybernik, Knuckles the Echidna and Robotnik. Despite the changes, the cover head disappeared after Issue 86 and would only return three more times before Issue 100. A makeover in Issue 104 saw the cover head becoming a permanent fixture, with Flint's Sonic being replaced with the image from the cover of Sonic 3D. Lasting all the way to Issue 175, this would change into the Sonic Adventure cover for the rest of STC's run.
Sonic the Comic Online
Sonic the Comic Online returned with this feature, although the image changed frequently to feature different characters and artists. The idea was a lot less rigid, with the image moving about and being altered on occasion - the Hallowe'en edition of Issue 227 saw Sonic replaced with his skeleton, while Issue 245 stated that Knuckles was "not featuring" this issue (referencing his recent death, although the cover head was lying).
As of Issue 250, the cover heads no longer feature. A poll was posted in the Message Zone by Mike Corker which asked if people would like to see them return (actually giving the Cover Heads their name). Out of 50 participants, eight expressed apathy towards them, three wouldn't have minded their return but a staggering 39 saw them as an integral part of the classic STC and clamoured for their return. No voters explicitly said they didn't want them to return, but, as of Issue 255, they have not come back. Nevertheless, alternate voters claimed they didn't see that they had gone, and few had raised this point earlier (with Adamis, artist of several unused cover heads, being one of them).
The cover head returned in Issue 259, once again with the declaration "Starring Sonic the Hedgehog" and an image of the hero's head.