Death Bird is a member of the Birds alongside Bomb Bird, Time Bird, and Ice Bird, as well as an unknown number of others. Unlike the others, Death Bird became obsessed with power and killed most of the Birds. Since Time Bird exists in all timelines and can travel between the timelines, he is essentially immortal. For that reason, Death Bird hunts him down. At one point, Death Bird defeats Ice Bird and the Bird gets frozen in the Frozen Forest. Millions of years in the future, Mario and Luigi free Ice Bird. Later on, Death Bird gets sent to jail, alongside Bomb Bird. Death Bird eventually breaks free and begins studying the Warp Zone in order to figure out Time Bird's powers. Death Bird then comes across Yellow Yoshi, and kidnaps him for use as a test subject. Yellow Yoshi eventually got sent into the Paranormal Dimension, where he met his fate. In 2029, Death Bird managed to capture Time Bird and create an army to take over the Mushroom Kingdom. However, he's eventually defeated by Mario and Luigi.
- In the Terminator episode, the Death Bird sends a robot back in time using Time Bird's powers to kill Mario and Luigi. The robot fails and is destroyed.
- The Death Bird seems to exist in the Boring Adventures dimension.
- Time Bird and Death Bird seem to have a rivalry of sorts.