The Comedian's Button is a yellow smiley face pin, worn by Edward Blake.
It is one of the most iconic and recognizable images from the Watchmen comic.
The Comedian wore the badge on his robe the night he was attacked in his apartment. When Blake was beaten, his blood stained the badge in its familiar pattern: a single line of blood across the badge's left eye. When Blake was thrown out of the window, the badge flew free off of him and was washed into the gutter. It remained there until Rorschach came across it the night after the murder.
Rorschach later gave the badge to Daniel Dreiberg when he came to inform him of Blake's death. Dreiberg removed the blood and kept the badge with him. At Blake's funeral, Dreiberg dropped the badge into Blake's grave, on top of the coffin.
Flash eventually recieved a call from Batman, informing him that the radiation from the button had spiked and torn a hole in the Speed Force. Before Flash is able to arrive, the Reverse-Flash arrives at the cave and beats Batman to a pulp. Reverse-Flash then goes to examine the button, and just as he begins to look at it, he is seemingly teleported out of the Batcave and back a moment later, burning in blue flames, and claiming that he had seen God. The Reverse-Flash then collapsed and seemingly died.
Later, after Batman and the Flash had visited the Flashpoint universe and escaped before it was erased from existence, they began traveling through the timestream, where they encountered Thawne once more, although they had gone back in time just before he was killed. Thawne was seen holding the button and told Batman and Flash that he knows who holds the true power it, and that he was on his way to face them, claiming they had never faced someone like him.
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