Unus Annus is a collaborative experimental YouTube vlog channel created in November 15, 2019 by YouTube artists Mark Edward Fischbach better known as the creator of the gaming commentary channel, Markiplier, and Ethan Mark Nestor-Darling, creator of CrankGamePlays. The theme of the channel revolved around the inevitability of death and mostly revolved around doing everything one wanted to do before death in many vlog-style videos. Together they uploaded a video everyday throughout the year performing var. To embrace this theme, every single episode started and ended with a digital clock that was counting down. Once the clock reached zero, the channel including all of the videos and content would be deleted.