A few months ago, Robert Kirkman, the creator of the "walking dead", spoke that Glenn would die in the season 6. At first glance it seems that this has already happened - in the 3rd series, which has been broadcast on Sunday, October 25, 2015. However, not everything is so simple: Glenn, perhaps still not died and will appear in episodes in the future.
In the official statement, the executive producer of "Walking Dead" Scott M. Gimple clearly made it clear that, in one way or another, Stephen Yen, who played the role of Glenn for 6 seasons of the series, will return to his character in the future. Of course, no details of the gimple did not disclose, so until it is not clear to the end, in which the quality of Glenn returns to the "Walking Dead" - perhaps, he did not die at all, perhaps, the audience will see him in one of the flash stacks or even in New quality of one of the many zombies. According to the plot of comics, which is more or less follows the plot of the series, Glenn dies from the hand of the Negan - and this character will appear in the "walking dead" only in the final (in the last, 16th series of the 6th season).