"All the time [people] save, they lose to us. We drain it off, we hoard it, we thirst for it. Human beings have no conception of the value of their time, but we do. We suck them dry, and we need more and more time every day, because there are more and more of us. More and more and more. . ."
Rikku (Final Fantasy X-2); via the Thief Dressphere
Yuna (Final Fantasy X-2); via the Thief Dressphere
Paine (Final Fantasy X-2); via the Thief Dressphere
The Men in Grey/The Grey Gentlemen/Time Thieves (Momo)
Ryuk (Death Note) is a Shinigami, a god of death who survive by killing humans to extend their own lives, by using their Death Notes.
In the In Time universe humans can steal (or give in some cases) time from each other. If their clocks run down to zero, death is immediate.
Henry Hamilton (In Time) is exactly 105 years old but looks only 25.
The Weeping Angels (Doctor Who) steal life by sending people back in time. They live off the remaining time energy of the victim's life.
Timebreaker (Miraculous Ladybug) has the power to gain the ability to travel through time through a number of minutes equal to the number of people she touches, freezing them in time and causing them to fade from existence.
Charlotte Linlin (One Piece) taking 40 years of Moscato's lifespan, killing him.
Kurumi Tokisaki (Date A Live) can absorb the lifespan of others people via the City of Devouring Time.
The Grey Gentlemen (Momo) are so-called Time Thieves who steal time from humanity by manipulating them into saving time as cigars made of saved time are their source of life energy