Malachi Constant is a fictional character from the science fiction novel "The Sirens of Titan" by Kurt Vonnegut. He is portrayed as a wealthy and carefree man who becomes embroiled in a cosmic journey that explores themes of free will, fate, and the meaning of life. His adventures take him across the universe, revealing the absurdity of existence. Throughout the story, Malachi's experiences are influenced by the mysterious Winston Niles Rumfoord, who has the ability to see the past, present, and future. This connection leads Malachi to confront his own purpose and the larger forces at play in the universe, ultimately challenging his understanding of destiny.