Dogtooth

Dogtooth (mostly reffered as Optimism or Rage) is a character that appears first in Continue?, appearing to kill the Puppet God.

Dogtooth is a wolf-like humanoid creature with a spiky head. It is revealed in his debut that these spikes are in fact knives.

During the series, Dogtooth never speaks. But his actions speak much louder than any words ever spoken in the entire series. In [Continue?] he peers into the continue button to see the Puppet God dancing and sporadically moving before taking out one of the knives from his head and stabbing him. Behind the Puppet God is the word, "quit," and behind Dogtooth is the word, "continue." This could represent the feeling to continue on with life overpowering the thought to commit suicide.

In the next video featuring Dogtooth, Zoning Ordinance, Dogtooth appears to be burying the corpse of the Puppet God. As he is about to do so, he breaks out into a fight with the Quilled God. Halfway through the fight we hear a heart monitor going silent before Dogtooth rips his own heart out and pumping it to make the monitor start beeping again. These two videos establish Dogtooth's violent and shameless personality well. The restarting of his heart could also be seen as going to a therapist or a reality check to start up his life again. Ultimately, both of them lost the fight to Room.

After this fight, in A Love Letter, Dogtooth is angry at Room for causing him to lose the fight. Throughout the entire video, he tries to Murder Room. Then soon after kills him by stabbing him in the chest after talking to The Angel then tells him "I love you" in ASL.