Tralfamadorian (Slaughterhouse-Five)

Tralfamadorians are an alien species from the planet Tralfamadore which can see all of time simultaneously: past, present and future.

Their appearance is similar to a green toilet plunger, about 2 ft tall, with a suction cup at the base and a flexible shaft. At the end of the shaft there is a single hand, with a single eye on its palm.

Their complete awareness of the future gives them a radically different perspective to life, as they know that the future is fixed and can't be changed. As for the past, they see nothing depressing about death, as to them, the past is just as vivid as the future, and everyone who ever was alive will always be alive to them.